Stephen J. Galli, MD
Mary Hewitt Loveless, MD, Professor in the School of Medicine and Professor of Pathology and of Microbiology and Immunology
Bio
In 1999, I became chair of the Department of Pathology (and finished my tenure in that role on April 30, 2016), the Mary Hewitt Loveless, MD Professor, and a professor of pathology and of microbiology and immunology at Stanford University School of Medicine. I am also a member of the Executive Committee of the Stanford Institute for Immunity, Transplantation and Infection. From 2009-2016, while chair of pathology, I also was Co-Director of the Stanford Center for Genomics and Personalized Medicine.
I received a BA in biology in 1968 from Harvard College, a BMS in 1970 from Dartmouth Medical School (then a two year school) and the MD in 1973 from Harvard Medical School (HMS), and completed a residency and chief residency in Anatomic Pathology at Massachusetts General Hospital (MGH) in 1977. After postdoctoral training with Harold F. Dvorak at MGH, I joined the HMS faculty in 1979 as assistant professor of pathology, became professor of pathology in 1993, and, until moving to Stanford, served as director of the Division of Experimental Pathology at Beth Israel Deaconess Medical Center and a member of the HMS Committee on Immunology.
My research focuses on the development and function of mast cells and basophils (major effector cells in allergic disorders) and the development of new animal models for studying the roles of these cells in health and disease. I have particular interests in the roles of these cells in anaphylaxis, food allergies, and asthma, and in the roles of mast cells and IgE in innate and acquired host defense against venoms.
Academic Appointments
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Professor, Pathology
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Professor, Microbiology & Immunology
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Member, Bio-X
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Member, Cardiovascular Institute
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Member, Stanford Cancer Institute
Administrative Appointments
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Chair, Stanford University School of Medicine - Pathology (1999 - 2016)
Honors & Awards
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Dottorato di Ricerca Honoris Causa in Medicina Clinica e Sperimentale (Honorary PhD), University of Naples Federico II (2019)
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Karl Landsteiner Medal, Austrian Society of Allergology and Immunology (2014)
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Rous-Whipple Award, American Society for Investigative Pathology (2014)
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Scientific Achievement Award, World Allergy Organization (2011)
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Faculty Mentor Award for Postdoctoral Education, Immunology Program, Stanford University School of Medicine (2010)
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President’s Award for Excellence Through Diversity, Stanford University (2010)
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Highly Cited Researcher (Immunology), ISI Highly Cited (2006)
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Scientific Achievement Award, International Association of Allergy & Clinical Immunology (1997)
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MERIT Award (AI/CA 23990, "Regulation of mast cell development and function"), NIAID/NIH (1995-2006)
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Karin Grunebaum Cancer Research Foundation Fellowship, Harvard Medical School (1971-1972)
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B.M.S. with honors, Dartmouth Medical School (1970)
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B.A., magna cum laude in Biology, Harvard College (1968)
Boards, Advisory Committees, Professional Organizations
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Foreign Member, Società Nazionale di Scienze, Lettere e Arti (2019 - Present)
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Member, Sigma Xi (2017 - Present)
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Overseas Fellow, Royal Society of Medicine (London) (2017 - Present)
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Fellow, Center for Innovation in Global Health, Stanford University (2016 - Present)
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Member, American Clinical and Climatological Association (2015 - Present)
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Member, National Allergy and Infectious Diseases Council of the National Institutes of Health (2014 - 2019)
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Board of Consulting Editors, Journal of Clinical Investigation (2012 - Present)
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Member, National Academy of Medicine (2010 - Present)
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Editorial Board, The Annual Review of Pathology: Mechanisms of Disease (2004 - Present)
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Foreign Member in the Physical, Mathematical, and Natural Sciences Class, Accademia Nazionale dei Lincei (2001 - Present)
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Editorial Board, Laboratory Investigation (1997 - Present)
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Member, Association of American Physicians (1997 - Present)
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Advisory Editor, Journal of Experimental Medicine (1993 - 2011)
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Member, American Society for Clinical Investigation (1991 - Present)
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Member; Past: President, Pluto Club (Association of University Pathologists (1986 - Present)
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Member of Council; Past: President, Vice President, Secretary, Collegium Internationale Allergologicum (1984 - Present)
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Member; Past: President, Vice President, American Society for Investigative Pathology (1982 - Present)
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Member, American Association of Immunologists (1980 - Present)
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Fellow, American Association for the Advancement of Science (1975 - Present)
Current Research and Scholarly Interests
Mast cells, which normally reside in the tissues, and basophils, which circulate in the blood, are major effector cells of asthma and other IgE-associated allergic disorders (e.g., anaphylaxis, food allergy, allergic rhinitis, atopic dermatitis, and asthma) and in immune responses to parasites. However, mast cells also have been implicated (as effector and/or immunoregulatory cells) in many other settings.
For example, our lab has shown that mast cells can enhance innate and acquired immune responses that help to reduce the toxicity and mortality induced by arthropod and reptile venoms, which may represent a major evolutionary benefit of mast cells (and IgE antibodies). There also is evidence that mast cells can contribute to host responses to pathogens other than parasites, such as bacteria and viruses, and can have potential beneficial or harmful effects in diverse immnunological or inflammatory disorders that are not thought to involve IgE. Finally, mast cells have been implicated in many processes that maintain homeostasis or regulate tissue remodeling, such as angiogenesis, wound healing, the regulation of epithelial and mesenchymal cell development and function, and interactions with sensory nerves.
The goals of Dr. Galli's laboratory are to develop and employ genetic approaches in mice to understand the regulation of mast cell and basophil development and the expression of mast cell and basophil function, and to elucidate the roles of these cells in health and disease. In parallel with these mouse studies, we investigate the roles of mast cells and basophils in human health and disease by conducting studies of human mast cells and basophils in vitro, or by analyzing specimens derived from patients with food allergy, asthma, atopic dermatitis, or other disorders in which mast cells or basophils have been implicated.
In addition to studies focused on mast cells and basophils, the Galli lab also analyzes immunological mechanisms which underlie the development of severe allergies, such as those to certain foods, and the immunological regulatory mechanisms that can be engaged therapeutically to reduce the severity of these disorders or ameliorate them, e.g., via the induction of desensitization or tolerance. Finally, we are attempting to define "biomarkers", such as changes in the levels of surface structures on circulating basophils, which can be used to monitor the severity of allergic disorders and/or the patients' responses to immunotherapy or other therapeutic interventions.
2024-25 Courses
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Independent Studies (14)
- Directed Reading in Immunology
IMMUNOL 299 (Aut, Win, Spr, Sum) - Directed Reading in Microbiology and Immunology
MI 299 (Aut, Win, Spr, Sum) - Directed Reading in Pathology
PATH 299 (Aut, Win, Spr, Sum) - Early Clinical Experience in Immunology
IMMUNOL 280 (Aut, Win, Spr, Sum) - Early Clinical Experience in Pathology
PATH 280 (Aut, Win, Spr, Sum) - Graduate Research
IMMUNOL 399 (Aut, Win, Spr, Sum) - Graduate Research
MI 399 (Aut, Win, Spr, Sum) - Graduate Research
PATH 399 (Aut, Win, Spr, Sum) - Medical Scholars Research
MI 370 (Aut, Win, Spr, Sum) - Medical Scholars Research
PATH 370 (Aut, Win, Spr, Sum) - Teaching in Immunology
IMMUNOL 290 (Aut, Win, Spr, Sum) - Undergraduate Research
IMMUNOL 199 (Aut, Win, Spr, Sum) - Undergraduate Research
MI 199 (Aut, Win, Spr, Sum) - Undergraduate Research
PATH 199 (Aut, Win, Spr, Sum)
- Directed Reading in Immunology
All Publications
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Baseline Epitope-Specific IgE Profiles are Predictive of Sustained Unresponsiveness or High Threshold One-Year Post OIT in the POISED Trial.
The Journal of allergy and clinical immunology
2024
Abstract
BACKGROUND: Results from the POISED trial suggest that discontinuation of peanut oral immunotherapy can increase the risk of regaining clinical reactivity to peanut.OBJECTIVE: We sought to determine whether those who achieved sustained unresponsiveness (SU) or sustained high threshold (SHT) have different baseline sequential epitope-specific (es-) IgE profiles than those who achieved transient desensitization (TD).METHODS: Subjects in the POISED trial (NCT02103270) were randomized to peanut (n=95) or placebo (n=25) for 24 months. OIT-desensitized subjects were then assigned to no peanut (PN-0, n=51) or 300mg (PN-300, n=30) for 12 months. SU and SHT were determined by those in PN-0 and PN-300, respectively, passing 4000mg peanut oral challenge. Specific IgE and IgG4 levels to peanut, Ara h 1-3 proteins and 64 allergenic epitopes were measured. We developed machine learning glmnet models with bootstrap simulations using baseline data to predict SU/SHT.RESULTS: Eighty (84%) subjects were desensitized to peanut. Of those, 13% (n=8) and 37% (n=13) achieved SU/SHT in PN-0 and PN-300. Decreases in epitope-and protein-specific IgE levels and increases in IgG4 levels were observed during 2 years of OIT. At baseline, patients with SU in Peanut-0 but not Peanut-300 had lower es-IgE and protein-sIgE levels compared to the TD group. A machine-learning model with 12 baseline es-IgEs and age could predict SU/SHT with an accuracy of 94%, AUC 0.97, Sensitivity 1.00, Specificity 0.91.CONCLUSIONS: Patients who achieved SU/SHT have different baseline protein-and epitope-specific IgE profiles than those with TD. These profiles may help identify patients with an increased likelihood of achieving SU/SHT.
View details for DOI 10.1016/j.jaci.2024.10.017
View details for PubMedID 39505279
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Role of allergen immunotherapy and biologics in allergic diseases.
Current opinion in immunology
2024; 91: 102494
Abstract
The rise in the prevalence of allergic diseases has become a global health burden. Allergic diseases are a group of immune-mediated disorders characterized by IgE-mediated conditions resulting from a type 2 helper T cell (Th2)-skewed immune response. This review aims to comprehensively summarize recent research on the roles of allergen immunotherapy (AIT) and biologics in allergic diseases. Specifically, we review the mechanisms of AIT and biologics in modulating innate and adaptive immunity involved in allergic disease pathogenesis, as well as their safety and efficacy in the treatment of allergic diseases. We also discuss current new AIT strategies such as recombinant allergen-based vaccines and allergen extract nanoencapsulation. Further research is needed to understand immune tolerance mechanisms beyond the Th2 pathway and to characterize immunological changes in responders and nonresponders to AIT or biologics. This additional research may uncover new targets for monitoring treatment responses and developing personalized treatment strategies for allergic diseases.
View details for DOI 10.1016/j.coi.2024.102494
View details for PubMedID 39357079
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Association of cytotoxic effector memory CD8+ T cells with sustained unresponsiveness after peanut oral immunotherapy.
Allergy
2024
View details for DOI 10.1111/all.16307
View details for PubMedID 39244697
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Harmonization of Diagnostic Criteria in Mastocytosis for Use in Clinical Practice: WHO vs ICC vs AIM/ECNM.
The journal of allergy and clinical immunology. In practice
2024
Abstract
Mastocytosis is a clonal myeloid disorder defined by an increase and accumulation of mast cells (MC) in one or multiple organ systems. The complex pathology of mastocytosis results in variable clinical presentations, courses, and outcomes. The World Health Organization (WHO) divides the disease into cutaneous mastocytosis (CM), several forms of systemic mastocytosis (SM), and MC sarcoma. In most SM patients, a somatic KIT mutation, usually D816V, is identified. Patients diagnosed with CM or non-advanced SM, including indolent SM, have a near-normal life-expectancy, whereas those with advanced SM, including aggressive SM and MC leukemia, have limited life-expectancy. Since 2001, a multidisciplinary consensus group consisting of experts from the European Competence Network on Mastocytosis (ECNM) and American Initiative in Mast Cell Diseases (AIM), has supported the field by developing diagnostic criteria for mastocytosis. These criteria served as the basis for the WHO classification of mastocytosis over two decades. More recently, an international consensus group (ICC) proposed slightly modified diagnostic criteria and a slightly revised classification. In this article, these changes are discussed. Furthermore, we propose harmonization among the proposals of the AIM/ECNM consensus group, WHO, and ICC. Such harmonization will facilitate comparisons of retrospective study results and the conduct of prospective trials.
View details for DOI 10.1016/j.jaip.2024.08.044
View details for PubMedID 39216803
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Elucidating allergic reaction mechanisms in response to SARS-CoV-2 mRNA vaccination in adults.
Allergy
2024
Abstract
During the COVID-19 pandemic, novel nanoparticle-based mRNA vaccines were developed. A small number of individuals developed allergic reactions to these vaccines although the mechanisms remain undefined.To understand COVID-19 vaccine-mediated allergic reactions, we enrolled 19 participants who developed allergic events within 2 h of vaccination and 13 controls, nonreactors. Using standard hemolysis assays, we demonstrated that sera from allergic participants induced stronger complement activation compared to nonallergic subjects following ex vivo vaccine exposure.Vaccine-mediated complement activation correlated with anti-polyethelyne glycol (PEG) IgG (but not IgM) levels while anti-PEG IgE was undetectable in all subjects. Depletion of total IgG suppressed complement activation in select individuals. To investigate the effects of vaccine excipients on basophil function, we employed a validated indirect basophil activation test that stratified the allergic populations into high and low responders. Complement C3a and C5a receptor blockade in this system suppressed basophil response, providing strong evidence for complement involvement in vaccine-mediated basophil activation. Single-cell multiome analysis revealed differential expression of genes encoding the cytokine response and Toll-like receptor (TLR) pathways within the monocyte compartment. Differential chromatin accessibility for IL-13 and IL-1B genes was found in allergic and nonallergic participants, suggesting that in vivo, epigenetic modulation of mononuclear phagocyte immunophenotypes determines their subsequent functional responsiveness, contributing to the overall physiologic manifestation of vaccine reactions.These findings provide insights into the mechanisms underlying allergic reactions to COVID-19 mRNA vaccines, which may be used for future vaccine strategies in individuals with prior history of allergies or reactions and reduce vaccine hesitancy.
View details for DOI 10.1111/all.16231
View details for PubMedID 39033312
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Mast cell beta1 integrin localizes mast cells in close proximity to blood vessels and enhances their rapid responsiveness to intravenous antigen.
The Journal of allergy and clinical immunology
2024
View details for DOI 10.1016/j.jaci.2024.07.009
View details for PubMedID 39038588
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Mast cell secretory granule fusion with amphisomes coordinates their homotypic fusion and release of exosomes.
Cell reports
2024; 43 (7): 114482
Abstract
Secretory granule (SG) fusion is an intermediate step in SG biogenesis. However, the precise mechanism of this process is not completely understood. We show that Golgi-derived mast cell (MC) SGs enlarge through a mechanism that is dependent on phosphoinositide (PI) remodeling and fusion with LC3+ late endosomes (amphisomes), which serve as hubs for the fusion of multiple individual SGs. Amphisome formation is regulated by the tyrosine phosphatase PTPN9, while the subsequent SG fusion event is additionally regulated by the tetraspanin protein CD63 and by PI4K. We also demonstrate that fusion with amphisomes imparts to SGs their capacity of regulated release of exosomes. Finally, we show that conversion of PI(3,4,5)P3 to PI(4,5)P2 and the subsequent recruitment of dynamin stimulate SG fission. Our data unveil a key role for lipid-regulated interactions with the endocytic and autophagic systems in controlling the size and number of SGs and their capacity to release exosomes.
View details for DOI 10.1016/j.celrep.2024.114482
View details for PubMedID 38985670
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The origins, manifestations, and potential treatments of allergic disorders.
Seminars in immunology
2024; 73: 101886
View details for DOI 10.1016/j.smim.2024.101886
View details for PubMedID 38875768
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Mast Cell Activation Syndrome: current understanding and research needs.
The Journal of allergy and clinical immunology
2024
Abstract
Mast cell activation syndrome (MCAS) is a term applied to several clinical entities which have gained increased attention from patients and medical providers. While several descriptive publications about MCAS exist, there are many gaps in knowledge resulting in confusion about this clinical syndrome. Whether MCAS is a primary syndrome or exists as a constellation of symptoms in the context of known inflammatory, allergic, or clonal disorders associated with systemic mast cell (MC) activation is not well understood. More importantly, the underlying mechanisms and pathways that lead to MC activation in MCAS patients remain to be elucidated. The purpose of this manuscript is to summarize the known literature, identify gaps in knowledge, and highlight research needs. Several topics are covered: 1) Contextualization of MCAS and MCAS-like endotypes and related diagnostic evaluations; 2) Mechanistic research; 3) Management of typical and refractory symptoms, and 4) MCAS-specific education for patients and healthcare providers.
View details for DOI 10.1016/j.jaci.2024.05.025
View details for PubMedID 38851398
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Mast cells: a novel therapeutic avenue for cardiovascular diseases?
Cardiovascular research
2024
Abstract
Mast cells are tissue-resident immune cells strategically located in different compartments of the normal human heart (the myocardium, pericardium, aortic valve and close to nerves) as well as in atherosclerotic plaques. Cardiac mast cells produce a broad spectrum of vasoactive and proinflammatory mediators, which have potential roles in inflammation, angiogenesis, lymphangiogenesis, tissue remodeling and fibrosis. Mast cells release preformed mediators (e.g., histamine, tryptase, chymase) and de novo synthesized mediators [e.g., cysteinyl leukotriene C4 (LTC4) and prostaglandin D2 (PGD2)], as well as cytokines and chemokines, which can activate different resident immune cells (e.g., macrophages) and structural cells (e.g., fibroblasts, endothelial cells) in the human heart and aorta. The transcriptional profiles of various mast cell populations highlight their potential heterogeneity and distinct gene and proteome expression. Mast cell plasticity and/or heterogeneity enable these cells the potential for performing different, even opposite, functions in response to changing tissue contexts. Human cardiac mast cells display significant differences compared to mast cells isolated from other organs. These characteristics make cardiac mast cells intriguing, given their dichotomous potential roles of inducing or protecting against cardiovascular diseases. Identification of cardiac mast cell subpopulations represents a prerequisite for understanding their potential multifaceted roles in health and disease. Several new drugs specifically targeting human mast cell activation are under development or in clinical trials. Mast cells and/or their subpopulations can potentially represent novel therapeutic targets for cardiovascular disorders.
View details for DOI 10.1093/cvr/cvae066
View details for PubMedID 38630620
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Efficacy of peanut oral immunotherapy is not impacted by the development of persistent gastrointestinal symptoms
MOSBY-ELSEVIER. 2024: AB121
View details for Web of Science ID 001267526000375
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Spatiotemporal Immune Cells Profiling in Gastrointestinal Tissue Biopsies to Detect Oral Immunotherapy Induced Changes in Peanut Allergic Individuals
MOSBY-ELSEVIER. 2024: AB371
View details for Web of Science ID 001267526000853
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Epigenetic Mechanisms In Allergic Diseases During Pregnancy
MOSBY-ELSEVIER. 2024: AB376
View details for Web of Science ID 001267526000868
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Can artificial intelligence (AI) replace oral food challenge?
The Journal of allergy and clinical immunology
2024
View details for DOI 10.1016/j.jaci.2024.01.008
View details for PubMedID 38262500
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Combining avidin with CD63 improves basophil activation test accuracy in classifying peanut allergy.
Allergy
2023
Abstract
Conventional basophil activation tests (BATs) measure basophil activation by the increased expression of CD63. Previously, fluorophore-labeled avidin, a positively-charged molecule, was found to bind to activated basophils, which tend to expose negatively charged granule constituents during degranulation. This study further compares avidin versus CD63 as basophil activation biomarkers in classifying peanut allergy.Seventy subjects with either a peanut allergy (N = 47), a food allergy other than peanut (N = 6), or no food allergy (N = 17) were evaluated. We conducted BATs in response to seven peanut extract (PE) concentrations (0.01-10,000 ng/mL) and four control conditions (no stimulant, anti-IgE, fMLP (N-formylmethionine-leucyl-phenylalanine), and anti-FcεRI). We measured avidin binding and CD63 expression on basophils with flow cytometry. We evaluated logistic regression and XGBoost models for peanut allergy classification and feature identification.Avidin binding was correlated with CD63 expression. Both markers discriminated between subjects with and without a peanut allergy. Although small by percentage, an avidin+ /CD63- cell subset was found in all allergic subjects tested, indicating that the combination of avidin and CD63 could allow a more comprehensive identification of activated basophils. Indeed, we obtained the best classification accuracy (97.8% sensitivity, 96.7% specificity) by combining avidin and CD63 across seven PE doses. Similar accuracy was obtained by combining PE dose of 10,000 ng/mL for avidin and PE doses of 10 and 100 ng/mL for CD63.Avidin and CD63 are reliable BAT activation markers associated with degranulation. Their combination enhances the identification of activated basophils and improves the classification accuracy of peanut allergy.
View details for DOI 10.1111/all.15930
View details for PubMedID 37916710
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EVO756 is a novel MRGPRX2 antagonist that potently inhibits human mast cell degranulation in response to multiple agonists - potential treatment for CSU and beyond
ELSEVIER SCIENCE INC. 2023: S344
View details for Web of Science ID 001106031700069
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Nomenclature of allergic diseases and hypersensitivity reactions: Adapted to modern needs: An EAACI position paper.
Allergy
2023
Abstract
The exponential growth of precision diagnostic tools, including omic technologies, molecular diagnostics, sophisticated genetic and epigenetic editing, imaging and nano-technologies and patient access to extensive health care, has resulted in vast amounts of unbiased data enabling in-depth disease characterization. New disease endotypes have been identified for various allergic diseases and triggered the gradual transition from a disease description focused on symptoms to identifying biomarkers and intricate pathogenetic and metabolic pathways. Consequently, the current disease taxonomy has to be revised for better categorization. This European Academy of Allergy and Clinical Immunology Position Paper responds to this challenge and provides a modern nomenclature for allergic diseases, which respects the earlier classifications back to the early 20th century. Hypersensitivity reactions originally described by Gell and Coombs have been extended into nine different types comprising antibody- (I-III), cell-mediated (IVa-c), tissue-driven mechanisms (V-VI) and direct response to chemicals (VII). Types I-III are linked to classical and newly described clinical conditions. Type IVa-c are specified and detailed according to the current understanding of T1, T2 and T3 responses. Types V-VI involve epithelial barrier defects and metabolic-induced immune dysregulation, while direct cellular and inflammatory responses to chemicals are covered in type VII. It is notable that several combinations of mixed types may appear in the clinical setting. The clinical relevance of the current approach for allergy practice will be conferred in another article that will follow this year, aiming at showing the relevance in clinical practice where various endotypes can overlap and evolve over the lifetime.
View details for DOI 10.1111/all.15889
View details for PubMedID 37814905
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Landscape of mast cell populations across organs in mice and humans.
The Journal of experimental medicine
2023; 220 (10)
Abstract
Mast cells (MCs) are tissue-resident immune cells that exhibit homeostatic and neuron-associated functions. Here, we combined whole-tissue imaging and single-cell RNA sequencing datasets to generate a pan-organ analysis of MCs in mice and humans at steady state. In mice, we identify two mutually exclusive MC populations, MrgprB2+ connective tissue-type MCs and MrgprB2neg mucosal-type MCs, with specific transcriptomic core signatures. While MrgprB2+ MCs develop in utero independently of the bone marrow, MrgprB2neg MCs develop after birth and are renewed by bone marrow progenitors. In humans, we unbiasedly identify seven MC subsets (MC1-7) distributed across 12 organs with different transcriptomic core signatures. MC1 are preferentially enriched in the bladder, MC2 in the lungs, and MC4, MC6, and MC7 in the skin. Conversely, MC3 and MC5 are shared by most organs but not skin. This comprehensive analysis offers valuable insights into the natural diversity of MC subtypes in both mice and humans.
View details for DOI 10.1084/jem.20230570
View details for PubMedID 37462672
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The normal range of baseline tryptase should be 1-15 ng/ml and covers healthy individuals with hereditary alpha tryptasemia.
The journal of allergy and clinical immunology. In practice
2023
Abstract
Physiologic levels of basal serum tryptase vary among healthy individuals, depending on the numbers of mast cells, basal secretion rate, copy numbers of the TPSAB1 gene encoding alpha tryptase, and renal function. Recently, there has been a growing debate about the normal range of tryptase because individuals with the hereditary alpha tryptasemia (HαT) trait may or may not be symptomatic, and if symptomatic, uncertainty exists as to whether this trait directly causes clinical phenotypes or aggravates certain conditions. In fact, most HαT-positive cases are regarded asymptomatic concerning MC activation. To address this point, experts of the European Competence Network on Mastocytosis (ECNM) and the American Initiative on Mast Cell Diseases met at the 2022 Annual ECNM meeting and discussed the physiologic tryptase range. Based on this discussion, our faculty concluded that the ´normal serum tryptase range´ should be defined in asymptomatic controls, inclusive of individuals with HαT, and based on 2 standard deviations covering the 95% confidence interval. By applying this definition in a literature screen, the normal basal tryptase in asymptomatic controls (HαT-positive persons included) ranges between 1 and 15 ng/mL. This definition should avoid over-interpretation, unnecessary referrals, and unnecessary anxiety or anticipatory fear of illness in healthy individuals.
View details for DOI 10.1016/j.jaip.2023.08.008
View details for PubMedID 37572755
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Conditional neutrophil depletion challenges their contribution to mouse models of anaphylaxis.
Allergy
2023
View details for DOI 10.1111/all.15738
View details for PubMedID 37022292
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Baseline Epitope-Specific IgE Profiles are Predictive of Sustained Unresponsiveness One Year Post OIT in the POISED Trial
MOSBY-ELSEVIER. 2023: AB120
View details for Web of Science ID 000991651900371
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Multiplexed Tissue Imaging for Immune Cells Profiling During Peanut Allergy Immunotherapy
MOSBY-ELSEVIER. 2023: AB34
View details for Web of Science ID 000991651900101
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Allergy: Mechanistic insights into new methods of prevention and therapy
SCIENCE TRANSLATIONAL MEDICINE
2023; 15 (679)
View details for Web of Science ID 000932397900005
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Allergy: Mechanistic insights into new methods of prevention and therapy.
Science translational medicine
2023; 15 (679): eadd2563
Abstract
In the past few decades, the prevalence of allergic diseases has increased worldwide. Here, we review the etiology and pathophysiology of allergic diseases, including the role of the epithelial barrier, the immune system, climate change, and pollutants. Our current understanding of the roles of early life and infancy; diverse diet; skin, respiratory, and gut barriers; and microbiome in building immune tolerance to common environmental allergens has led to changes in prevention guidelines. Recent developments on the mechanisms involved in allergic diseases have been translated to effective treatments, particularly in the past 5 years, with additional treatments now in advanced clinical trials.
View details for DOI 10.1126/scitranslmed.add2563
View details for PubMedID 36652536
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CD8+ T cell differentiation status correlates with the feasibility of sustained unresponsiveness following oral immunotherapy.
Nature communications
2022; 13 (1): 6646
Abstract
While food allergy oral immunotherapy (OIT) can provide safe and effective desensitization (DS), the immune mechanisms underlying development of sustained unresponsiveness (SU) following a period of avoidance are largely unknown. Here, we compare high dimensional phenotypes of innate and adaptive immune cell subsets of participants in a previously reported, phase 2 randomized, controlled, peanut OIT trial who achieved SU vs. DS (no vs. with allergic reactions upon food challenge after a withdrawal period; n=21 vs. 30 respectively among total 120 intent-to-treat participants). Lower frequencies of naive CD8+ T cells and terminally differentiated CD57+CD8+ T cell subsets at baseline (pre-OIT) are associated with SU. Frequency of naive CD8+ T cells shows a significant positive correlation with peanut-specific and Ara h 2-specific IgE levels at baseline. Higher frequencies of IL-4+ and IFNgamma+ CD4+ T cells post-OIT are negatively correlated with SU. Our findings provide evidence that an immune signature consisting of certain CD8+ T cell subset frequencies is potentially predictive of SU following OIT.
View details for DOI 10.1038/s41467-022-34222-8
View details for PubMedID 36333296
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New Insights Into the Pathogenesis of Mastocytosis: Emerging Concepts in Diagnosis and Therapy.
Annual review of pathology
2022
Abstract
Mastocytosis is a heterogeneous group of neoplasms defined by a numerical increase and accumulation of clonal mast cells (MCs) in various organ systems. The disease may present as cutaneous mastocytosis or systemic mastocytosis (SM). On the basis of histopathological and molecular features, clinical variables, and organ involvement, SM is divided into indolent SM, smoldering SM, SM with an associated hematologic neoplasm, aggressive SM, and MC leukemia. Each variant is defined by unique diagnostic criteria and a unique spectrum of clinical presentations. A key driver of MC expansion and disease evolution is the oncogenic machinery triggered by mutant forms of KIT. The genetic background, additional somatic mutations, and comorbidities also contribute to the course and prognosis. Patients with SM may also suffer from mediator-related symptoms or even an MC activation syndrome. This article provides an update of concepts on the genetics, etiology, and pathology of mastocytosis, with emphasis on diagnostic criteria and new treatment concepts. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 18 is January 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
View details for DOI 10.1146/annurev-pathmechdis-031521-042618
View details for PubMedID 36270293
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IN MEMORIAM : Lawrence M. Lichtenstein (1934-2022).
Allergy
2022
View details for DOI 10.1111/all.15549
View details for PubMedID 36219503
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An optimized protocol for phenotyping human granulocytes by mass cytometry.
STAR protocols
2022; 3 (2): 101280
Abstract
Granulocytes encompass diverse roles, from fighting off pathogens to regulating inflammatory processes in allergies. These roles are represented by distinct cellular phenotypes that we captured with mass cytometry (CyTOF). Our protocol enables simultaneous evaluation of human basophils, eosinophils, and neutrophils under homeostasis and upon immune activation by anti-Immunoglobulin E (anti-IgE) or interleukin-3 (IL-3). Granulocyte integrity and detection of protein markers were optimized so that rare granulocyte populations could be deeply characterized by single cell mass cytometry. For complete details on the use and execution of this protocol, please refer to Vivanco Gonzalez etal. (2020).
View details for DOI 10.1016/j.xpro.2022.101280
View details for PubMedID 35434655
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Dynamin Related Protein 1 Differentially Regulates FcepsilonRI- and SP-induced Mast Cell Activation.
The Journal of allergy and clinical immunology
2022
Abstract
BACKGROUND: The mitochondrial fission protein, dynamin related protein 1 (Drp1), has been suggested to regulate mast cell (MC) activation by certain stimuli in vitro but its functions in MCs activated by various stimuli in vivo has not been examined.OBJECTIVE: Analyze Drp1 function in both mouse and human MCs.METHODS: We used human peripheral blood-derived cultured MCs (PBCMCs) and two genetic mouse models in which MCs were depleted of Drp1: Drp1fl/flMcpt5cre+/- mice and Drp1fl/flCpa3cre+/- mice.RESULTS: In mice, Drp1 depletion enhanced FcepsilonRI-induced MC activation while suppressing substance P (SP)-stimulated MC activation in vitro and in vivo. This was also true in human PBCMCs in vitro after pharmacological inhibition of Drp1.CONCLUSION: Our work shows that Drp1 differentially regulates MC activation by various stimuli. These findings suggest that promoting Drp1 activation might represent a novel therapy for suppressing IgE-dependent MC activation while inhibiting Drp1 activation might mitigate other MC-dependent responses, such as those induced by substance P.
View details for DOI 10.1016/j.jaci.2022.04.028
View details for PubMedID 35561839
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KIT as a master regulator of the mast cell lineage.
The Journal of allergy and clinical immunology
2022
Abstract
The discovery in 1987/1988 and 1990 of the cell-surface receptor KIT and its ligand, stem cell factor (SCF), were critical achievements in efforts to understand the development and function of multiple distinct cell lineages. These include hematopoietic progenitors, melanocytes, germ cells, and mast cells, which all are significantly affected by loss-of-function mutations of KIT or SCF. Such mutations also influence the development and/or function of additional cells, including those in parts of the CNS and the interstitial cells of Cajal (that control gut motility). Many other cells can express KIT constitutively or during immune responses, including dendritic cells, eosinophils, ILC2 cells, and taste cells. Yet the biological importance of KIT in many of these cell types largely remains to be determined. We here review the history of work investigating mice with mutations affecting the W locus (that encodes KIT) or the Sl locus (that encodes SCF), focusing especially on the influence of such mutations on mast cells. We also briefly review efforts to target the KIT/SCF pathway with anti-SCF or anti-KIT antibodies in mouse models of allergic disorders, parasite immunity, or fibrosis in which MCs are thought to play significant roles.
View details for DOI 10.1016/j.jaci.2022.04.012
View details for PubMedID 35469840
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Exponential magnetophoretic gradient for the direct isolation of basophils from whole blood in a microfluidic system.
Lab on a chip
2022
Abstract
Despite their rarity in peripheral blood, basophils play important roles in allergic disorders and other diseases including sepsis and COVID-19. Existing basophil isolation methods require many manual steps and suffer from significant variability in purity and recovery. We report an integrated basophil isolation device (i-BID) in microfluidics for negative immunomagnetic selection of basophils directly from 100 muL of whole blood within 10 minutes. We use a simulation-driven pipeline to design a magnetic separation module to apply an exponentially increasing magnetic force to capture magnetically tagged non-basophils flowing through a microtubing sandwiched between magnetic flux concentrators sweeping across a Halbach array. The exponential profile captures non-basophils effectively while preventing their excessive initial buildup causing clogging. The i-BID isolates basophils with a mean purity of 93.9% ± 3.6% and recovery of 95.6% ± 3.4% without causing basophil degradation or unintentional activation. Our i-BID has the potential to enable basophil-based point-of-care diagnostics such as rapid allergy assessment.
View details for DOI 10.1039/d2lc00154c
View details for PubMedID 35438713
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Drug-Induced Mast Cell Eradication: A Novel Approach to Treat Mast Cell Activation Disorders?
The Journal of allergy and clinical immunology
2022
Abstract
Mast cell activation is a key event in allergic reactions, other inflammatory states, and mast cell activation syndromes. Mast cell-stabilizing agents, mediator-targeting drugs and drugs interfering with mediator effects are often prescribed in these patients. However, the clinical efficacy of these drugs varies, depending on the numbers of involved mast cells and the underlying pathology. One straightforward approach would be to eradicate the primary target cell. However, to date, no mast cell-eradicating treatment approach has been developed for patients suffering from mast cell activation disorders. Nevertheless, recent data suggest that long-term treatment with agents that effectively inhibit KIT-function results in the virtual eradication of tissue mast cells and a sustained decrease in serum tryptase levels. In many of these patients, mast cell depletion is associated with a substantial improvement in mediator-induced symptoms. In patients with an underlying KIT D816V+ mastocytosis, such mast cell eradication requires an effective inhibitor of KIT D816V, such as avapritinib. However, the use of KIT inhibitors must be balanced against potential side effects. We here discuss mast cell-eradicating strategies in various disease models, the feasibility of this approach, available clinical data, and future prospects for the use of KIT-targeting drugs in mast cell activation disorders.
View details for DOI 10.1016/j.jaci.2022.04.003
View details for PubMedID 35421448
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Development of Basophil Activation Test (BAT)-based point-of-care diagnostic tool for allergies
MOSBY-ELSEVIER. 2022: AB48
View details for Web of Science ID 000778999300142
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Gastrointestinal γδ T cells reveal differentially expressed transcripts and enriched pathways during peanut oral immunotherapy.
Allergy
2022
View details for DOI 10.1111/all.15250
View details for PubMedID 35143054
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Mast cells partly contribute to allergic enteritis development: findings in two different mast cell-deficient mice.
Allergy
2021
View details for DOI 10.1111/all.15182
View details for PubMedID 34807472
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Updated Diagnostic Criteria and Classification of Mast Cell Disorders: A Consensus Proposal.
HemaSphere
2021; 5 (11): e646
Abstract
Mastocytosis is a hematologic neoplasm characterized by expansion and focal accumulation of neoplastic mast cells (MC) in diverse organs, including the skin, bone marrow (BM), spleen, liver, and gastrointestinal tract. The World Health Organization classification divides the disease into prognostically distinct variants of cutaneous mastocytosis (CM) and systemic mastocytosis (SM). Although this classification remains valid, recent developments in the field and the advent of new diagnostic and prognostic parameters created a need to update and refine definitions and diagnostic criteria in MC neoplasms. In addition, MC activation syndromes (MCAS) and genetic features predisposing to SM and MCAS have been identified. To discuss these developments and refinements in the classification, we organized a Working Conference comprised of experts from Europe and the United States in August 2020. This article reports on outcomes from this conference. Of particular note, we propose adjustments in the classification of CM and SM, refinements in diagnostic criteria of SM variants, including smoldering SM and BM mastocytosis (BMM), and updated criteria for MCAS and other conditions involving MC. CD30 expression in MC now qualifies as a minor SM criterion, and BMM is now defined by SM criteria, absence of skin lesions and absence of B- and C-findings. A basal serum tryptase level exceeding 20 ng/mL remains a minor SM criterion, with recognition that hereditary alpha-tryptasemia and various myeloid neoplasms may also cause elevations in tryptase. Our updated proposal will support diagnostic evaluations and prognostication in daily practice and the conduct of clinical trials in MC disorders.
View details for DOI 10.1097/HS9.0000000000000646
View details for PubMedID 34901755
View details for PubMedCentralID PMC8659997
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The longitudinal basophil activation tests predict long-term safety and efficacy of peanut OIT therapy
WILEY. 2021: 7
View details for Web of Science ID 000718612200014
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Updated Diagnostic Criteria and Classification of Mast Cell Disorders: A Consensus Proposal
HEMASPHERE
2021; 5 (11)
View details for DOI 10.1097/HS9.0000000000000646
View details for Web of Science ID 000714988300001
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Neutrophil-specific gain-of-function mutations in Nlrp3 promote development of cryopyrin-associated periodic syndrome.
The Journal of experimental medicine
2021; 218 (10)
Abstract
Gain-of-function mutations in NLRP3 are responsible for a spectrum of autoinflammatory diseases collectively referred to as "cryopyrin-associated periodic syndromes" (CAPS). Treatment of CAPS patients with IL-1-targeted therapies is effective, confirming a central pathogenic role for IL-1beta. However, the specific myeloid cell population(s) exhibiting inflammasome activity and sustained IL-1beta production in CAPS remains elusive. Previous reports suggested an important role for mast cells (MCs) in this process. Here, we report that, in mice, gain-of-function mutations in Nlrp3 restricted to neutrophils, and to a lesser extent macrophages/dendritic cells, but not MCs, are sufficient to trigger severe CAPS. Furthermore, in patients with clinically established CAPS, we show that skin-infiltrating neutrophils represent a substantial biological source of IL-1beta. Together, our data indicate that neutrophils, rather than MCs, can represent the main cellular drivers of CAPS pathology.
View details for DOI 10.1084/jem.20201466
View details for PubMedID 34477811
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Assessment of Allergic and Anaphylactic Reactions to mRNA COVID-19 Vaccines With Confirmatory Testing in a US Regional Health System.
JAMA network open
2021; 4 (9): e2125524
Abstract
Importance: As of May 2021, more than 32 million cases of COVID-19 have been confirmed in the United States, resulting in more than 615 000 deaths. Anaphylactic reactions associated with the Food and Drug Administration (FDA)-authorized mRNA COVID-19 vaccines have been reported.Objective: To characterize the immunologic mechanisms underlying allergic reactions to these vaccines.Design, Setting, and Participants: This case series included 22 patients with suspected allergic reactions to mRNA COVID-19 vaccines between December 18, 2020, and January 27, 2021, at a large regional health care network. Participants were individuals who received at least 1 of the following International Statistical Classification of Diseases and Related Health Problems, Tenth Revision anaphylaxis codes: T78.2XXA, T80.52XA, T78.2XXD, or E949.9, with documentation of COVID-19 vaccination. Suspected allergy cases were identified and invited for follow-up allergy testing.Exposures: FDA-authorized mRNA COVID-19 vaccines.Main Outcomes and Measures: Allergic reactions were graded using standard definitions, including Brighton criteria. Skin prick testing was conducted to polyethylene glycol (PEG) and polysorbate 80 (P80). Histamine (1 mg/mL) and filtered saline (negative control) were used for internal validation. Basophil activation testing after stimulation for 30 minutes at 37 °C was also conducted. Concentrations of immunoglobulin (Ig) G and IgE antibodies to PEG were obtained to determine possible mechanisms.Results: Of 22 patients (20 [91%] women; mean [SD] age, 40.9 [10.3] years; 15 [68%] with clinical allergy history), 17 (77%) met Brighton anaphylaxis criteria. All reactions fully resolved. Of patients who underwent skin prick tests, 0 of 11 tested positive to PEG, 0 of 11 tested positive to P80, and 1 of 10 (10%) tested positive to the same brand of mRNA vaccine used to vaccinate that individual. Among these same participants, 10 of 11 (91%) had positive basophil activation test results to PEG and 11 of 11 (100%) had positive basophil activation test results to their administered mRNA vaccine. No PEG IgE was detected; instead, PEG IgG was found in tested individuals who had an allergy to the vaccine.Conclusions and Relevance: Based on this case series, women and those with a history of allergic reactions appear at have an elevated risk of mRNA vaccine allergy. Immunological testing suggests non-IgE-mediated immune responses to PEG may be responsible in most individuals.
View details for DOI 10.1001/jamanetworkopen.2021.25524
View details for PubMedID 34533570
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The role of Sp140 revealed in IgE and mast cell responses in Collaborative Cross mice.
JCI insight
2021; 6 (12)
Abstract
Mouse IgE and mast cell (MC) functions have been studied primarily using inbred strains. Here, we (a) identified effects of genetic background on mouse IgE and MC phenotypes, (b) defined the suitability of various strains for studying IgE and MC functions, and (c) began to study potentially novel genes involved in such functions. We screened 47 Collaborative Cross (CC) strains, as well as C57BL/6J and BALB/cJ mice, for strength of passive cutaneous anaphylaxis (PCA) and responses to the intestinal parasite Strongyloides venezuelensis (S.v.). CC mice exhibited a diversity in PCA strength and S.v. responses. Among strains tested, C57BL/6J and CC027 mice showed, respectively, moderate and uniquely potent MC activity. Quantitative trait locus analysis and RNA sequencing of BM-derived cultured MCs (BMCMCs) from CC027 mice suggested Sp140 as a candidate gene for MC activation. siRNA-mediated knock-down of Sp140 in BMCMCs decreased IgE-dependent histamine release and cytokine production. Our results demonstrated marked variations in IgE and MC activity in vivo, and in responses to S.v., across CC strains. C57BL/6J and CC027 represent useful models for studying MC functions. Additionally, we identified Sp140 as a gene that contributes to IgE-dependent MC activation.
View details for DOI 10.1172/jci.insight.146572
View details for PubMedID 34156030
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Accurate and Reproducible Diagnosis of Peanut Allergy Using Epitope Mapping.
Allergy
2021
Abstract
BACKGROUND: Accurate diagnosis of peanut allergy is a significant clinical challenge. Here, a novel diagnostic blood test using the peanut Bead-Based Epitope Assay ("peanut BBEA") was developed utilizing the LEAP cohort and then validated using two independent cohorts.METHODS: The development of the peanut BBEA diagnostic test followed the National Academy of Medicine's established guidelines with discovery performed on 133 subjects from the non-interventional arm of the LEAP trial and an independent validation performed on 82 subjects from the CoFAR2 and 84 subjects from the POISED study. All samples were analyzed using the peanut BBEA methodology,which measures levels of IgE to two Ara h 2 sequential (linear) epitopes and compares their combination to a threshold pre-specified in the model development phase. When a patient has an inconclusive outcome by skin prick testing(or sIgE), IgE antibody levelsto this combination of two epitopes candistinguish whether the patient is "Allergic" or "Not Allergic." Diagnoses of peanut allergy in all subjects were confirmed by double-blind placebo-controlled food challenge and subjects' ages were 7-55 years.RESULTS: In the validation usingCoFAR2 and POISED cohorts, the peanut BBEA diagnostic test correctly diagnosed 93% of the subjects, with a sensitivity of 91%, specificity of 95%, a positive predictive value of 95% and negative predictive value of 91%.CONCLUSIONS: In validation of the peanut BBEA diagnostic test, the overall accuracy was found to be superior to existing diagnostic tests for peanut allergy including skin prick testing, peanut sIgE and peanut component sIgE testing.
View details for DOI 10.1111/all.14905
View details for PubMedID 33991353
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IgE antibodies increase honeybee venom responsiveness and detoxification efficiency of mast cells.
Allergy
2021
Abstract
BACKGROUND: In contrast to theirclearly defined rolesin allergic diseases, the physiologic functions of Immunoglobulin E antibodies (IgEs) and mast cells (MCs) remainenigmatic. Recent research supports the toxin hypothesis,showing thatMCs and IgE-related type 2 immune responses can enhance host defense against certain noxious substances, including honeybee venom (BV). However, the mechanisms by whichMCs can interfere with BV toxicity are unknown. In this study, we assessed the role of IgE andcertain MC products inMC-mediated BV detoxification.METHODS: We appliedin vitro and in vivofluorescence microscopyimaging, andflow cytometry,fibroblast-based toxicity assaysand mass spectrometry to investigate IgE-mediated detoxification of BV cytotoxicity by mouse and human MCs in vitro. Pharmacologic strategies to interfere with MC-derived heparin and proteaseshelped to define the importance of specific detoxification mechanisms.RESULTS: Venom-specific IgE increased the degranulation and cytokineresponses of MCs to BVin vitro. Passive serum sensitization enhanced MC degranulationin vivo. IgE-activated mouse or human MCs exhibited enhanced potential for detoxifying BV by both proteolytic degradation and heparin-related interference with toxicity.Mediators released by IgE-activated human MCs efficiently degraded multiple BV toxins.CONCLUSIONS: Our results both revealthat IgEsensitization enhances the MC's ability to detoxify BVand alsoassign efficienttoxin-neutralizing activity to MC-derivedheparin and proteases. Our study thus highlights the potential importance of IgE, MCs, and particular MC products in defense against BV.
View details for DOI 10.1111/all.14852
View details for PubMedID 33840121
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Immune Changes Beyond Th2 Pathways During Rapid Multifood Immunotherapy enabled with Omalizumab.
Allergy
2021
Abstract
BACKGROUND: Multifood Oral Immunotherapy (mOIT) with adjunctive anti-IgE (omalizumab, Xolair ) treatment affords safe, effective, and rapid desensitization to multiple foods, although the specific immune mechanisms mediating this desensitization remain to be fully elucidated.METHODS: Participants in our phase 2 mOIT trial (NCT02643862) received omalizumab from baseline to week 16 and mOIT from week 8 to week 36. We compared the immune profile of PBMCs and plasma taken at baseline, week 8 and week 36 using high-dimensional mass cytometry, component-resolved diagnostics, the indirect basophil activation test, and Luminex.RESULTS: We found (i) decreased frequency of IL4+ peanut-reactive CD4+ T cells and a marked downregulation of GPR15 expression and CXCR3 frequency among gammadelta and CD8+ T cell subsets at week 8 during the initial, omalizumab-alone induction phase; (ii) significant upregulation of the skin-homing receptor CCR4 in peanut-reactive CD4+ T and Th2 effector memory (EM) cells and of cutaneous lymphocyte-associated antigen (CLA) in peanut-reactive CD8+ T and CD8+ EM cells (iii) downregulation of CD86 expression among antigen-presenting cell subsets; and (iv) reduction in pro-inflammatory cytokines, notably IL-17, at week 36 post-OIT. We also observed significant attenuation of the Th2 phenotype post-OIT, defined by downregulation of IL-4 peanut-reactive T cells and OX40 in Th2EM cells, increased allergen component-specific IgG4/IgE ratio, and decreased allergen-driven activation of indirectly sensitized basophils.CONCLUSIONS: This exploratory study provides novel comprehensive insight into the immune underpinnings of desensitization through omalizumab-facilitated mOIT. Moreover, this study provides encouraging results to support the complex immune changes that can be induced by OIT.
View details for DOI 10.1111/all.14833
View details for PubMedID 33782956
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Proceedings from the Inaugural American Initiative in Mast Cell Diseases (AIM) Investigator Conference.
The Journal of allergy and clinical immunology
2021
Abstract
The American Initiative in Mast Cell Diseases (AIM) held its inaugural investigator conference at Stanford University School of Medicine in May 2019. The overarching goal of this meeting was to establish a Pan-American organization of physicians and scientists with multidisciplinary expertise in mast cell disease. To serve this unmet need, AIM envisions a network where basic, translational, and clinical researchers could establish collaborations with both academia and biopharma to support the development of new diagnostic methods, enhanced understanding of the biology of mast cells in human health and disease, and the testing of novel therapies. In these AIM proceedings, we highlight selected topics relevant to mast cell biology and provide updates regarding the recently described hereditary alpha-tryptasemia. In addition, we discuss the evaluation and treatment of mast cell activation (syndromes), allergy and anaphylaxis in mast cell disorders, and the clinical and biologic heterogeneity of the more indolent forms of mastocytosis. As mast cell disorders are relatively rare, AIM hopes not only to achieve a coordination of scientific efforts in the Americas, but also in Europe by collaborating with the well-established European Competence Network on Mastocytosis (ECNM).
View details for DOI 10.1016/j.jaci.2021.03.008
View details for PubMedID 33745886
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Basophil activation tests identify a peanut OIT subgroup with improved safety and outcomes
MOSBY-ELSEVIER. 2021: AB166
View details for Web of Science ID 000629158000529
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Transcriptome programmingof IL-3-dependent bone marrow-derived cultured mast cells by stem cell factor (SCF).
Allergy
2021
View details for DOI 10.1111/all.14808
View details for PubMedID 33683709
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Proposed Diagnostic Criteria and Classification of Canine Mast Cell Neoplasms: A Consensus Proposal.
Frontiers in veterinary science
1800; 8: 755258
Abstract
Mast cell neoplasms are one of the most frequently diagnosed malignancies in dogs. The clinical picture, course, and prognosis vary substantially among patients, depending on the anatomic site, grade and stage of the disease. The most frequently involved organ is the skin, followed by hematopoietic organs (lymph nodes, spleen, liver, and bone marrow) and mucosal sites of the oral cavity and the gastrointestinal tract. In cutaneous mast cell tumors, several grading and staging systems have been introduced. However, no comprehensive classification and no widely accepted diagnostic criteria have been proposed to date. To address these open issues and points we organized a Working Conference on canine mast cell neoplasms in Vienna in 2019. The outcomes of this meeting are summarized in this article. The proposed classification includes cutaneous mast cell tumors and their sub-variants defined by grading- and staging results, mucosal mast cell tumors, extracutaneous/extramucosal mast cell tumors without skin involvement, and mast cell leukemia (MCL). For each of these entities, diagnostic criteria are proposed. Moreover, we have refined grading and staging criteria for mast cell neoplasms in dogs based on consensus discussion. The criteria and classification proposed in this article should greatly facilitate diagnostic evaluation and prognostication in dogs with mast cell neoplasms and should thereby support management of these patients in daily practice and the conduct of clinical trials.
View details for DOI 10.3389/fvets.2021.755258
View details for PubMedID 34957277
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Letter by Varricchi et al Regarding Article, "Role of IgE-FcεR1 in Pathological Cardiac Remodeling and Dysfunction".
Circulation
2021; 144 (13): e214-e215
View details for DOI 10.1161/CIRCULATIONAHA.121.055167
View details for PubMedID 34570593
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E-cadherin is regulated by GATA-2 and marks the early commitment of mouse hematopoietic progenitors to the basophil and mast cell fates.
Science immunology
2021; 6 (56)
Abstract
E-cadherin is a calcium-dependent cell-cell adhesion molecule extensively studied for its involvement in tissue formation, epithelial cell behavior, and suppression of cancer. However, E-cadherin expression in the hematopoietic system has not been fully elucidated. Combining single-cell RNA-sequencing analyses and immunophenotyping, we revealed that progenitors expressing high levels of E-cadherin and contained within the granulocyte-monocyte progenitors (GMPs) fraction have an enriched capacity to differentiate into basophils and mast cells. We detected E-cadherin expression on committed progenitors before the expression of other reported markers of these lineages. We named such progenitors pro-BMPs (pro-basophil and mast cell progenitors). Using RNA sequencing, we observed transcriptional priming of pro-BMPs to the basophil and mast cell lineages. We also showed that GATA-2 directly regulates E-cadherin expression in the basophil and mast cell lineages, thus providing a mechanistic connection between the expression of this cell surface marker and the basophil and mast cell fate specification.
View details for DOI 10.1126/sciimmunol.aba0178
View details for PubMedID 33547048
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Basophil activation test shows high accuracy in the diagnosis of peanut and tree nut allergy: The Markers of Nut Allergy Study.
Allergy
2020
Abstract
BACKGROUND: Peanut and tree nut allergies are the most important causes of anaphylaxis. Co-reactivity to more than one nut is frequent, and co-sensitization in the absence of clinical data is often obtained. Confirmatory oral food challenges (OFCs) are inconsistently performed.OBJECTIVE: To investigate the utility of the basophil activation test (BAT) in diagnosing peanut and tree nut allergy.METHODS: The Markers Of Nut Allergy Study (MONAS) prospectively enrolled patients aged 0.5-17 years with confirmed peanut and/or tree nut (almond, cashew, hazelnut, pistachio, walnut) allergy or sensitization fromCanadian (n=150) and Austrian (n=50) tertiary pediatric centers. BAT using %CD63+ basophils (SSClow/CCR3pos) as outcome was performed with whole blood samples stimulated with allergen extracts of each nut (0.001-1000ng/mL protein). BAT results were assessed against confirmed allergic status in a blinded fashion to develop a generalizable statistical model for comparisonto extract and marker allergen-specificIgE.RESULTS: A mixed effect model integrating BAT results for 10 and 100 ng/mL of peanut and individual tree nut extracts was optimal. The area under the ROC curve (AUROC) was 0.98 for peanut, 0.97 for cashew, 0.92 for hazelnut, 0.95 for pistachio, and 0.97 for walnut. The BAT outperformed sIgE testing for peanut or hazelnut and was comparable for walnut (AUROC 0.95, 0.94, 0.92) ina sub-analysis in sensitized patients undergoing OFC.CONCLUSIONS: BAT can predict allergic clinical status to peanut and tree nuts in multi-nut sensitized children and may reduce the need for high-risk OFCs in patients.
View details for DOI 10.1111/all.14695
View details for PubMedID 33300157
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Mass Cytometry Phenotyping of Human Granulocytes Reveals Novel Basophil Functional Heterogeneity.
iScience
2020; 23 (11): 101724
Abstract
Basophils, the rarest granulocyte, play critical roles in parasite- and allergen-induced inflammation. We applied mass cytometry (CyTOF) to simultaneously asses 44 proteins to phenotype and functionally characterize neutrophils, eosinophils, and basophils from 19 healthy donors. There was minimal heterogeneity seen in eosinophils and neutrophils, but data-driven analyses revealed four unique subpopulations within phenotypically basophilic granulocytes (PBG; CD45+HLA-DR-CD123+). Through CyTOF and fluorescence-activated cell sorting (FACS), we classified these four PBG subpopulations as (I) CD16lowFcepsilonRIhighCD244high (88.5± 1.2%), (II) CD16highFcepsilonRIhighCD244high (9.1± 0.4%), (III) CD16lowFcepsilonRIlowCD244low (2.3± 1.3), and (IV) CD16highFcepsilonRIlowCD244low (0.4± 0.1%). Prospective isolation confirmed basophilic-morphology of PBG I-III, but neutrophilic-morphology of PBG IV. Functional interrogation via IgE-crosslinking or IL-3 stimulation demonstrated that PBG I-II had significant increases in CD203c expression, whereas PBG III-IV remained unchanged compared with media-alone conditions. Thus, PBG III-IV could serve roles in non-IgE-mediated immunity. Our findings offer new perspectives in human basophil heterogeneity and the varying functional potential of these new subsets in health and disease.
View details for DOI 10.1016/j.isci.2020.101724
View details for PubMedID 33205028
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Transcriptional changes in peanut-specific CD4+ T cells over the course of oral immunotherapy.
Clinical immunology (Orlando, Fla.)
2020: 108568
Abstract
Oral immunotherapy (OIT) can successfully desensitize allergic individuals to offending foods such as peanut. Our recent clinical trial (NCT02103270) of peanut OIT allowed us to monitor peanut-specific CD4+ T cells, using MHC-peptide Dextramers, over the course of OIT. We used a single-cell targeted RNAseq assay to analyze these cells at 0, 12, 24, 52, and 104 weeks of OIT. We found a transient increase in TGFbeta-producing cells at 52 weeks in those with successful desensitization, which lasted until 117 weeks. We also performed clustering and identified 5 major clusters of Dextramer+ cells, which we tracked over time. One of these clusters appeared to be anergic, while another was consistent with recently described TFH13 cells. The other 3 clusters appeared to be Th2 cells by their coordinated production of IL-4 and IL-13, but they varied in their expression of STAT signaling proteins and other markers. A cluster with high expression of STAT family members also showed a possible transient increase at week 24 in those with successful desensitization. Single cell TCRalphabeta repertoire sequences were too diverse to track clones over time. Together with increased TGFbeta production, these changes may be mechanistic predictors of successful OIT that should be further investigated.
View details for DOI 10.1016/j.clim.2020.108568
View details for PubMedID 32783912
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Repeated validation of a high performing peanut allergy diagnostic on POISED trial subjects
WILEY. 2020: 530
View details for Web of Science ID 000566847301444
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Differences in epitome response in peanut-allergic subjects treated with different immunotherapy preparations
WILEY. 2020: 101
View details for Web of Science ID 000566847300174
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Decrease in dose-related allergic reactions over time during peanut oral immunotherapy in a randomized phase 2 study
WILEY. 2020: 253
View details for Web of Science ID 000566847300465
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Eosinophilic gastrointestinal responses during peanut oral immunotherapy in a randomized controlled trial
WILEY. 2020: 12–13
View details for Web of Science ID 000566847300016
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Identification of cross-reactive allergens in cashew- and pistachio-allergic children during oral immunotherapy.
Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology
2020
Abstract
It has been estimated that around 8% of the children in the U.S. suffer from food allergy and of those, 40% are allergic to multiple foods. Among tree nuts, allergies to pistachios are common in those with cashew nut allergy and multiple homologous allergenic components are shared between the two nuts. Three major allergens from cashew (Ana o 1 at 50 kDa, Ana o 2 major band at 33 kDa and minor band at 53 kDa, and Ana o 3 at 10 kDa) and five major allergens from pistachio (Pis v 1 at 7 kDa, Pis v 2 at 32 kDa, Pis v 3 at 50 kDa, Pis v 4 at 23 kDa, and Pis v 5 at 36 kDa) have been identified. Of those, Ana o 1 and Pis v 3, Ana o 2 and Pis v 2, Ana o 2 and Pis v 5, Ana o 3 and Pis v 1 have been recognized as homologues based on their sequence similarity and cross reactivity to IgE from the patients.
View details for DOI 10.1111/pai.13258
View details for PubMedID 32323379
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Mast cells and IgE in defense against lethality of venoms: Possible "benefit" of allergy[].
Allergo journal international
2020; 29 (2): 46–62
Abstract
Physicians think of mast cells and IgE primarily in the context of allergic disorders, including fatal anaphylaxis. This 'bad side' of mast cells and IgE is so well accepted that it can be difficult to think of them in other contexts, particularly those in which they may have beneficial functions. However, there is evidence that mast cells and IgE, as well as basophils (circulating granulocytes whose functions partially overlap with those of mast cells), can contribute to host defense as components of adaptive type 2 immune responses to helminths, ticks and certain other parasites. Accordingly, allergies often are conceptualized as "misdirected" type 2 immune responses, in which IgE antibodies are produced against any of a diverse group of apparently harmless antigens, and against components of animal venoms. Indeed, certain unfortunate patients who have become sensitized to venoms develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. In this review, we will describe evidence that mast cells can enhance innate resistance, and survival, to challenge with reptile or arthropod venoms during a first exposure to such venoms. We also will discuss findings indicating that, in mice surviving an initial encounter with venom, acquired type 2 immune responses, IgE antibodies, the high affinity IgE receptor (FcepsilonRI), and mast cells can contribute to acquired resistance to the lethal effects of both honeybee venom and Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against venoms and perhaps other noxious substances.
View details for DOI 10.1007/s40629-020-00118-6
View details for PubMedID 33224714
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RNA-Seq of Gastrointestinal Biopsies During Oral Immunotherapy Reveals Changes in IgA Pathway
MOSBY-ELSEVIER. 2020: AB132
View details for Web of Science ID 000517092700419
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The TWEAK/Fn14 axis in anaphylactic shock.
The Journal of allergy and clinical immunology
2020; 145 (2): 491–93
View details for DOI 10.1016/j.jaci.2019.11.044
View details for PubMedID 32035606
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Sustained outcomes in oral immunotherapy for peanut allergy (POISED study): a large, randomised, double-blind, placebo-controlled, phase 2 study
MOSBY-ELSEVIER. 2020: AB181
View details for Web of Science ID 000517092700578
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Dose-related Allergic Reactions Decrease Over Time During Peanut Oral Immunotherapy in a Large, Randomized, Double-blind, Placebo-controlled, Phase 2 Study
MOSBY-ELSEVIER. 2020: AB134
View details for Web of Science ID 000517092700425
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Peanut oral immunotherapy induces gastrointestinal eosinophilia in a longitudinal randomized controlled trial
MOSBY-ELSEVIER. 2020: AB84
View details for Web of Science ID 000517092700258
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Butyrate inhibits human mast cell activation via epigenetic regulation of FcεRI-mediated signaling.
Allergy
2020
Abstract
Short-chain fatty acids (SCFAs) are fermented dietary components that regulate immune responses, promote colonic health and suppress mast cell-mediated diseases. However, the effects of SCFAs on human mast cell function, including the underlying mechanisms, remain unclear. Here, we investigated the effects of the SCFAs acetate, propionate and butyrate on mast cell-mediated pathology and human mast cell activation, including the molecular mechanisms involved.Precision-cut lung slices (PCLS) of allergen-exposed guinea pigs were used to assess the effects of butyrate on allergic airway contraction. Human and mouse mast cells were co-cultured with SCFAs and assessed for degranulation after IgE- or non-IgE-mediated stimulation. The underlying mechanisms involved were investigated using knockout mice, small molecule inhibitors/agonists, and genomics assays.Butyrate treatment inhibited allergen-induced histamine release and airway contraction in guinea pig PCLS. Propionate and butyrate, but not acetate, inhibited IgE and non-IgE-mediated human or mouse mast cell degranulation in a concentration-dependent manner. Notably, these effects were independent of the stimulation of SCFA receptors GPR41, GPR43 or PPAR, but instead were associated with inhibition of histone deacetylases. Transcriptome analyses revealed butyrate-induced downregulation of the tyrosine kinases BTK, SYK and LAT, critical transducers of FcεRI-mediated signals that are essential for mast cell activation. Epigenome analyses indicated that butyrate redistributed global histone acetylation in human mast cells, including significantly decreased acetylation at the BTK, SYK and LAT promoter regions.Known health benefits of SCFAs in allergic disease can, at least in part, be explained by epigenetic suppression of human mast cell activation.
View details for DOI 10.1111/all.14254
View details for PubMedID 32112426
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Microfluidic methods for precision diagnostics in food allergy.
Biomicrofluidics
2020; 14 (2): 021503
Abstract
Food allergy has reached epidemic proportions and has become a significant source of healthcare burden. Oral food challenge, the gold standard for food allergy assessment, often is not performed because it places the patient at risk of developing anaphylaxis. However, conventional alternative food allergy tests lack a sufficient predictive value. Therefore, there is a critical need for better diagnostic tests that are both accurate and safe. Microfluidic methods have the potential of helping one to address such needs and to personalize the diagnostics. This article first reviews conventional diagnostic approaches used in food allergy. Second, it reviews recent efforts to develop novel biomarkers and in vitro diagnostics. Third, it summarizes the microfluidic methods developed thus far for food allergy diagnosis. The article concludes with a discussion of future opportunities for using microfluidic methods for achieving precision diagnostics in food allergy, including multiplexing the detection of multiple biomarkers, sampling of tissue-resident cytokines and immune cells, and multi-organ-on-a-chip technology.
View details for DOI 10.1063/1.5144135
View details for PubMedID 32266046
View details for PubMedCentralID PMC7127910
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Increased diversity of gut microbiota during active oral immunotherapy in peanut allergic adults.
Allergy
2020
View details for DOI 10.1111/all.14540
View details for PubMedID 32750160
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A highly sensitive bioluminescent method for measuring allergen-specific IgE in microliter samples.
Allergy
2020
View details for DOI 10.1111/all.14365
View details for PubMedID 32407549
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Mast Cells in Inflammation and Disease: Recent Progress and Ongoing Concerns.
Annual review of immunology
2020; 38: 49–77
Abstract
Mast cells have existed long before the development of adaptive immunity, although they have been given different names. Thus, in the marine urochordate Styela plicata, they have been designated as test cells. However, based on their morphological characteristics (including prominent cytoplasmic granules) and mediator content (including heparin, histamine, and neutral proteases), test cells are thought to represent members of the lineage known in vertebrates as mast cells. So this lineage presumably had important functions that preceded the development of antibodies, including IgE. Yet mast cells are best known, in humans, as key sources of mediators responsible for acute allergic reactions, notably including anaphylaxis, a severe and potentially fatal IgE-dependent immediate hypersensitivity reaction to apparently harmless antigens, including many found in foods and medicines. In this review, we briefly describe the origins of tissue mast cells and outline evidence that these cells can have beneficial as well as detrimental functions, both innately and as participants in adaptive immune responses. We also discuss aspects of mast cell heterogeneity and comment on how the plasticity of this lineage may provide insight into its roles in health and disease. Finally, we consider some currently open questions that are yet unresolved.
View details for DOI 10.1146/annurev-immunol-071719-094903
View details for PubMedID 32340580
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IgE Effector Mechanisms, in Concert with Mast Cells, Contribute to Acquired Host Defense against Staphylococcusaureus.
Immunity
2020
Abstract
Allergies are considered to represent mal-directed type 2 immune responses against mostly innocuous exogenous compounds. Immunoglobulin E (IgE) antibodies are a characteristic feature of allergies and mediate hypersensitivity against allergens through activation of effector cells, particularly mast cells (MCs). Although the physiological functions of this dangerous branch of immunity have remained enigmatic, recent evidence shows that allergic immune reactions can help to protect against the toxicity of venoms. Because bacteria are a potent alternative source of toxins, we assessed the possible role of allergy-like type 2 immunity in antibacterial host defense. We discovered that the adaptive immune response against Staphylococcus aureus (SA) skin infection substantially improved systemic host defense against secondary SA infections in mice. Moreover, this acquired protection depended on IgE effector mechanisms and MCs. Importantly, our results reveal a previously unknown physiological function of allergic immune responses, IgE antibodies, and MCs in host defense against a pathogenic bacterium.
View details for DOI 10.1016/j.immuni.2020.08.002
View details for PubMedID 32910906
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Omalizumab in "non-IgE mediated" diseases.
The Journal of allergy and clinical immunology
2020
View details for DOI 10.1016/j.jaci.2020.10.033
View details for PubMedID 33160970
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Mast cells as a unique hematopoietic lineage and cell system: From Paul Ehrlich's visions to precision medicine concepts.
Theranostics
2020; 10 (23): 10743–68
Abstract
The origin and functions of mast cells (MCs) have been debated since their description by Paul Ehrlich in 1879. MCs have long been considered 'reactive bystanders' and 'amplifiers' in inflammatory processes, allergic reactions, and host responses to infectious diseases. However, knowledge about the origin, phenotypes and functions of MCs has increased substantially over the past 50 years. MCs are now known to be derived from multipotent hematopoietic progenitors, which, through a process of differentiation and maturation, form a unique hematopoietic lineage residing in multiple organs. In particular, MCs are distinguishable from basophils and other hematopoietic cells by their unique phenotype, origin(s), and spectrum of functions, both in innate and adaptive immune responses and in other settings. The concept of a unique MC lineage is further supported by the development of a distinct group of neoplasms, collectively referred to as mastocytosis, in which MC precursors expand as clonal cells. The clinical consequences of the expansion and/or activation of MCs are best established in mastocytosis and in allergic inflammation. However, MCs have also been implicated as important participants in a number of additional pathologic conditions and physiological processes. In this article, we review concepts regarding MC development, factors controlling MC expansion and activation, and some of the fundamental roles MCs may play in both health and disease. We also discuss new concepts for suppressing MC expansion and/or activation using molecularly-targeted drugs.
View details for DOI 10.7150/thno.46719
View details for PubMedID 32929378
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Origins and clonal convergence of gastrointestinal IgE+ B cells in human peanut allergy.
Science immunology
2020; 5 (45)
Abstract
B cells in human food allergy have been studied predominantly in the blood. Little is known about IgE+ B cells or plasma cells in tissues exposed to dietary antigens. We characterized IgE+ clones in blood, stomach, duodenum, and esophagus of 19 peanut-allergic patients, using high-throughput DNA sequencing. IgE+ cells in allergic patients are enriched in stomach and duodenum, and have a plasma cell phenotype. Clonally related IgE+ and non-IgE-expressing cell frequencies in tissues suggest local isotype switching, including transitions between IgA and IgE isotypes. Highly similar antibody sequences specific for peanut allergen Ara h 2 are shared between patients, indicating that common immunoglobulin genetic rearrangements may contribute to pathogenesis. These data define the gastrointestinal tract as a reservoir of IgE+ B lineage cells in food allergy.
View details for DOI 10.1126/sciimmunol.aay4209
View details for PubMedID 32139586
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Corrigendum: Analysis of a Large Standardized Food Challenge Data Set to Determine Predictors of Positive Outcome Across Multiple Allergens.
Frontiers in immunology
2020; 11: 625796
Abstract
[This corrects the article DOI: 10.3389/fimmu.2018.02689.].
View details for DOI 10.3389/fimmu.2020.625796
View details for PubMedID 33329616
View details for PubMedCentralID PMC7734876
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Rapid identification of human mast cell degranulation regulators using functional genomics coupled to high-resolution confocal microscopy.
Nature protocols
2020
Abstract
Targeted functional genomics represents a powerful approach for studying gene function in vivo and in vitro. However, its application to gene expression studies in human mast cells has been hampered by low yields of human mast cell cultures and their poor transfection efficiency. We developed an imaging system in which mast cell degranulation can be visualized in single cells subjected to shRNA knockdown or CRISPR-Cas9 gene editing. By using high-resolution confocal microscopy and a fluorochrome-labeled avidin probe, one can directly assess the alteration of functional responses, i.e., degranulation, in single human mast cells (10-12 weeks old). The elimination of a drug or marker selection step avoids the use of potentially toxic treatment procedures, and the brief hands-on time of the functional analysis step enables high-throughput screening of shRNA or CRISPR-Cas9 constructs to identify genes that regulate human mast cell degranulation. The ability to analyze single cells substantially reduces the total number of cells required and enables the parallel visualization of the degranulation profiles of both edited and non-edited mast cells, offering a consistent internal control not found in other protocols. Moreover, our protocol offers a flexible choice between RNA interference (RNAi) and CRISPR-Cas9 genome editing for perturbation of gene expression using our human mast cell single-cell imaging system. Perturbation of gene expression, acquisition of microscopy data and image analysis can be completed within 5 d, requiring only standard laboratory equipment and expertise.
View details for DOI 10.1038/s41596-019-0288-6
View details for PubMedID 32060492
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Oral Immunotherapy and Basophil and Mast Cell Reactivity in Food Allergy.
Frontiers in immunology
2020; 11: 602660
Abstract
Basophil activation tests (BATs) can closely monitor, in vitro, a patient's propensity to develop type I hypersensitivity reactions. Because of their high specificity and sensitivity, BATs have become promising diagnostic tools, especially in cases with equivocal clinical histories, skin prick test results, and/or levels of specific IgE to allergen extracts. BATs also are useful as tools for monitoring the effects of treatment, since oral immunotherapy (OIT) studies report a diminution in patients' basophil responsiveness over the course of OIT. This review will discuss the BAT findings obtained before, during, and after OIT for food allergy. We will mainly focus on the association of basophil responsiveness, and alterations in basophil surface markers, with clinical outcomes and other clinical features, such as blood levels of specific IgG and IgE antibodies. The detailed analysis of these correlations will ultimately facilitate the use of BATs, along with other blood biomarkers, to differentiate short-term desensitization versus sustained unresponsiveness and to improve treatment protocols. Given the critical anatomic location of mast cells adjacent to the many IgE+ plasma cells found in the gastrointestinal tissues of allergic individuals, we will also discuss the role of gastrointestinal mast cells in manifestations of food allergies.
View details for DOI 10.3389/fimmu.2020.602660
View details for PubMedID 33381123
View details for PubMedCentralID PMC7768812
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Trends in egg specific immunoglobulin levels during natural tolerance and oral immunotherapy.
Allergy
2019
View details for DOI 10.1111/all.14107
View details for PubMedID 31724180
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Adoptive Transfer of Basophils Enriched from Mouse Spleen
BIO-PROTOCOL
2019; 9 (21)
View details for DOI 10.21769/BioProtoc.3416
View details for Web of Science ID 000495082000009
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Adoptive Transfer of Basophils Enriched from Mouse Spleen.
Bio-protocol
2019; 9 (21): e3416
Abstract
CD49b is a member of the integrin family, expressed on basophils, natural killer (NK) cells and a subset CD4+ T cells in the spleen. This protocol describes the adoptive transfer of basophil-enriched CD49b+ cells obtained from mouse spleens by magnetic enrichment. This protocol can be used to assess the contribution of basophils or basophil-derived mediators to a certain immune response.
View details for DOI 10.21769/BioProtoc.3416
View details for PubMedID 33654915
View details for PubMedCentralID PMC7853924
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Conflicting verdicts on peanut OIT from the ICER and FDA Advisory Committee; where do we go from here?
The Journal of allergy and clinical immunology
2019
View details for DOI 10.1016/j.jaci.2019.10.021
View details for PubMedID 31678426
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Epithelial RABGEF1 deficiency promotes intestinal inflammation by dysregulating intrinsic MYD88-dependent innate signaling.
Mucosal immunology
2019
Abstract
Intestinal epithelial cells (IECs) contribute to the regulation of intestinal homeostasis and inflammation through their interactions with the environment and host immune responses. Yet our understanding of IEC-intrinsic regulatory pathways remains incomplete. Here, we identify the guanine nucleotide exchange factor RABGEF1 as a regulator of intestinal homeostasis and innate pathways dependent on IECs. Mice with IEC-specific Rabgef1 deletion (called Rabgef1IEC-KO mice) developed a delayed spontaneous colitis associated with the local upregulation of IEC chemokine expression. In mouse models of colitis based on Interleukin-10 deficiency or dextran sodium sulfate (DSS) exposure, we found that IEC-intrinsic RABGEF1 deficiency exacerbated development of intestinal pathology and dysregulated IEC innate pathways and chemokine expression. Mechanistically, we showed that RABGEF1 deficiency in mouse IECs in vitro was associated with an impairment of early endocytic events, an increased activation of the p38 mitogen-activated protein kinase (MAPK)-dependent pathway, and increased chemokine secretion. Moreover, we provided evidence that the development of spontaneous colitis was dependent on microbiota-derived signals and intrinsic MYD88-dependent pathways in vivo. Our study identifies mouse RABGEF1 as an important regulator of intestinal inflammation, MYD88-dependent IEC-intrinsic signaling, and chemokine production. This suggests that RABGEF1-dependent pathways represent interesting therapeutic targets for inflammatory conditions in the gut.
View details for DOI 10.1038/s41385-019-0211-z
View details for PubMedID 31628426
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Obituary for Teruko Ishizaka (1926-2019)
ALLERGOLOGY INTERNATIONAL
2019; 68 (4): 399–400
View details for DOI 10.1016/j.alit.2019.07.001
View details for Web of Science ID 000488955300001
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MIBI-TOF: A multiplexed imaging platform relates cellular phenotypes and tissue structure.
Science advances
2019; 5 (10): eaax5851
Abstract
Understanding tissue structure and function requires tools that quantify the expression of multiple proteins while preserving spatial information. Here, we describe MIBI-TOF (multiplexed ion beam imaging by time of flight), an instrument that uses bright ion sources and orthogonal time-of-flight mass spectrometry to image metal-tagged antibodies at subcellular resolution in clinical tissue sections. We demonstrate quantitative, full periodic table coverage across a five-log dynamic range, imaging 36 labeled antibodies simultaneously with histochemical stains and endogenous elements. We image fields of view up to 800 mum * 800 mum at resolutions down to 260 nm with sensitivities approaching single-molecule detection. We leverage these properties to interrogate intrapatient heterogeneity in tumor organization in triple-negative breast cancer, revealing regional variability in tumor cell phenotypes in contrast to a structured immune response. Given its versatility and sample back-compatibility, MIBI-TOF is positioned to leverage existing annotated, archival tissue cohorts to explore emerging questions in cancer, immunology, and neurobiology.
View details for DOI 10.1126/sciadv.aax5851
View details for PubMedID 31633026
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Mast cells are critical for controlling the bacterial burden and the healing of infected wounds.
Proceedings of the National Academy of Sciences of the United States of America
2019
Abstract
Skin wound infections are a significant health problem, and antibiotic resistance is on the rise. Mast cells (MCs) have been shown to contribute to host-defense responses in certain bacterial infections, but their role in skin wound superinfection is unknown. We subjected 2 MC-deficient mouse strains to Pseudomonas aeruginosa skin wound infection and found significantly delayed wound closure in infected skin wounds. This delay was associated with impaired bacterial clearance in the absence of MCs. Engraftment of MCs restored both bacterial clearance and wound closure. Bacterial killing was dependent on IL-6 released from MCs, and engraftment with IL-6-deficient MCs failed to control wound infection. Treatment with recombinant IL-6 enhanced bacterial killing and resulted in the control of wound infection and normal wound healing in vivo. Taken together, our results demonstrate a defense mechanism for boosting host innate immune responses, namely effects of MC-derived IL-6 on antimicrobial functions of keratinocytes.
View details for DOI 10.1073/pnas.1908816116
View details for PubMedID 31548430
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Future Needs in Mast Cell Biology.
International journal of molecular sciences
2019; 20 (18)
Abstract
The pathophysiological roles of mast cells are still not fully understood, over 140 years since their description by Paul Ehrlich in 1878. Initial studies have attempted to identify distinct "subpopulations" of mast cells based on a relatively small number of biochemical characteristics. More recently, "subtypes" of mast cells have been described based on the analysis of transcriptomes of anatomically distinct mouse mast cell populations. Although mast cells can potently alter homeostasis, in certain circumstances, these cells can also contribute to the restoration of homeostasis. Both solid and hematologic tumors are associated with the accumulation of peritumoral and/or intratumoral mast cells, suggesting that these cells can help to promote and/or limit tumorigenesis. We suggest that at least two major subsets of mast cells, MC1 (meaning anti-tumorigenic) and MC2 (meaning pro-tumorigenic), and/or different mast cell mediators derived from otherwise similar cells, could play distinct or even opposite roles in tumorigenesis. Mast cells are also strategically located in the human myocardium, in atherosclerotic plaques, in close proximity to nerves and in the aortic valve. Recent studies have revealed evidence that cardiac mast cells can participate both in physiological and pathological processes in the heart. It seems likely that different subsets of mast cells, like those of cardiac macrophages, can exert distinct, even opposite, effects in different pathophysiological processes in the heart. In this chapter, we have commented on possible future needs of the ongoing efforts to identify the diverse functions of mast cells in health and disease.
View details for DOI 10.3390/ijms20184397
View details for PubMedID 31500217
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Subclinical esophageal eosinophilia is present in some peanut allergic patients
WILEY. 2019: 97
View details for Web of Science ID 000480254000166
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Allergen-specific skin prick testing and IgE values adjusted for cumulative tolerated dose are predictive of oral food challenge outcomes across multiple allergens
WILEY. 2019: 150–51
View details for Web of Science ID 000480254001038
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Safety outcomes and differences in eliciting dose upon repeat oral food challenges in multi-food allergic individuals
WILEY. 2019: 801–2
View details for Web of Science ID 000480254004413
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A phase 2 randomized controlled study using omalizumab as an adjunct therapy during multi-allergen oral immunotherapy in food allergic individuals to test long-term outcomes
WILEY. 2019: 798–99
View details for Web of Science ID 000480254004406
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IgE-mediated mast cell activation promotes inflammation and cartilage destruction in osteoarthritis
ELIFE
2019; 8
View details for DOI 10.7554/eLife.39905
View details for Web of Science ID 000467895900001
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Meningeal Mast Cells as Key Effectors of Stroke Pathology.
Frontiers in cellular neuroscience
2019; 13: 126
Abstract
Stroke is the leading cause of adult disability in the United States. Because post-stroke inflammation is a critical determinant of damage and recovery after stroke, understanding the interplay between the immune system and the brain after stroke holds much promise for therapeutic intervention. An understudied, but important aspect of this interplay is the role of meninges that surround the brain. All blood vessels travel through the meningeal space before entering the brain parenchyma, making the meninges ideally located to act as an immune gatekeeper for the underlying parenchyma. Emerging evidence suggests that the actions of immune cells resident in the meninges are essential for executing this gatekeeper function. Mast cells (MCs), best known as proinflammatory effector cells, are one of the long-term resident immune cells in the meninges. Here, we discuss recent findings in the literature regarding the role of MCs located in the meningeal space and stroke pathology. We review the latest advances in mouse models to investigate the roles of MCs and MC-derived products in vivo, and the importance of using these mouse models. We examine the concept of the meninges playing a critical role in brain and immune interactions, reevaluate the perspectives on the key effectors of stroke pathology, and discuss the opportunities and challenges for therapeutic development.
View details for DOI 10.3389/fncel.2019.00126
View details for PubMedID 31001088
View details for PubMedCentralID PMC6457367
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Meningeal Mast Cells as Key Effectors of Stroke Pathology
FRONTIERS IN CELLULAR NEUROSCIENCE
2019; 13
View details for DOI 10.3389/fncel.2019.00126
View details for Web of Science ID 000463647300001
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Recruiting CD33 on mast cells to inhibit IgE-mediated mast cell-dependent anaphylaxis
JOURNAL OF CLINICAL INVESTIGATION
2019; 129 (3): 955–57
Abstract
IgE-mediated activation of mast cells is a hallmark of an anaphylactic reaction to allergen. In this issue of the JCI, Duan et al. describe an approach for suppressing IgE-dependent mast cell activation, thereby suppressing anaphylaxis. Specifically, the authors show that delivery of liposomes containing both the specific antigen recognized by the mast cell-bound IgE and a high-affinity glycan ligand of the inhibitory receptor CD33 (CD33L) to targeted mast cells inhibits antigen-induced, FcεRI-dependent spleen tyrosine kinase (Syk) phosphorylation and downstream protein tyrosine kinase (PTK) phosphorylation, Ca++ flux, and β-hexosaminidase release (i.e., degranulation). However, this strategy only worked if both the antigen (reactive with the mast cell-bound IgE) and CD33L were on the same liposome. This approach promises to rapidly reduce IgE-dependent mast cell activation in response to challenge with offending allergens.
View details for DOI 10.1172/JCI127100
View details for Web of Science ID 000460125800008
View details for PubMedID 30776022
View details for PubMedCentralID PMC6391104
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Complexities in analyzing human basophil responses to autoantibodies to IgE or Fc epsilon RI
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2019; 143 (3): 932-934
View details for DOI 10.1016/j.jaci.2018.12.998
View details for Web of Science ID 000460272900011
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Esophageal Eosinophilia is Present in Some Peanut Allergic Patients
MOSBY-ELSEVIER. 2019: AB310
View details for DOI 10.1016/j.jaci.2018.12.942
View details for Web of Science ID 000457771200928
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Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice
NATURE IMMUNOLOGY
2019; 20 (2): 129-+
View details for DOI 10.1038/s41590-018-0288-7
View details for Web of Science ID 000456279100011
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Immune Mechanism of Desensitization through Rapid Multi-food Oral Immunotherapy
MOSBY-ELSEVIER. 2019: AB254
View details for DOI 10.1016/j.jaci.2018.12.775
View details for Web of Science ID 000457771200763
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Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice.
Nature immunology
2019; 20 (2): 129–40
Abstract
Basophils are evolutionarily conserved in vertebrates, despite their small numbers and short life span, suggesting that they have beneficial roles in maintaining health. However, these roles are not fully defined. Here we demonstrate that basophil-deficient mice exhibit reduced bacterial clearance and increased morbidity and mortality in the cecal ligation and puncture (CLP) model of sepsis. Among the several proinflammatory mediators that we measured, tumor necrosis factor (TNF) was the only cytokine that was significantly reduced in basophil-deficient mice after CLP. In accordance with that observation, we found that mice with genetic ablation of Tnf in basophils exhibited reduced systemic concentrations of TNF during endotoxemia. Moreover, after CLP, mice whose basophils could not produce TNF, exhibited reduced neutrophil and macrophage TNF production and effector functions, reduced bacterial clearance, and increased mortality. Taken together, our results show that basophils can enhance the innate immune response to bacterial infection and help prevent sepsis.
View details for PubMedID 30664762
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Desensitization rates to peanut protein during OIT among children, adolescents, and adults
MOSBY-ELSEVIER. 2019: AB245
View details for DOI 10.1016/j.jaci.2018.12.750
View details for Web of Science ID 000457771200738
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Complexities in analyzing human basophil responses to auto-antibodies to IgE or FcepsilonRI.
The Journal of allergy and clinical immunology
2019
View details for PubMedID 30654052
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Development of multiple features of antigen-induced asthma pathology in a new strain of mast cell deficient BALB/c-KitW-sh/W-sh mice.
Laboratory investigation; a journal of technical methods and pathology
2019
Abstract
Mast cell-deficient mice are widely used to identify and quantify contributions of mast cells to diverse biological responses in vivo, including allergic inflammation. However, despite the fact that scores of genes have been identified as modifiers of allergic inflammation, most mast cell-deficient models have been available only on a single genetic background. We transferred the KitW-sh allele onto the BALB/c background to generate BALB/c mast cell-deficient mice (BALB/c-KitW-sh/W-sh). BALB/c-KitW-sh/W-sh mice have dramatically reduced mast cell numbers (0-2% of wild type) in all tissues examined, as well as subtle hematologic differences from the corresponding wild type mice, including splenomegaly with evidence of increased splenic hematopoiesis. We examined in BALB/c-KitW-sh/W-sh mice models of allergic inflammation that are substantially diminished in C57BL/6-KitW-sh/W-sh mast cell-deficient mice. In a model of acute allergic inflammation, i.e., IgE-dependent passive cutaneous anaphylaxis, both ear swelling and leukocyte infiltration were largely or entirely absent in BALB/c-KitW-sh/W-sh mice. In contrast, in two different models of allergic airway inflammation, airway hyperresponsiveness, lung inflammation, and airway remodeling developed robustly in mast cell-deficient BALB/c-KitW-sh/W-sh mice. These results support the conclusion that the importance of mast cell contributions in various models of allergic inflammation may be at least partially determined by genetic background.
View details for DOI 10.1038/s41374-019-0354-2
View details for PubMedID 31857699
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ICER report for peanut OIT comes up short.
Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology
2019
View details for DOI 10.1016/j.anai.2019.09.001
View details for PubMedID 31513908
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Sustained Successful Peanut Oral Immunotherapy Associated with Low Basophil Activation and Peanut-Specific IgE.
The Journal of allergy and clinical immunology
2019
Abstract
Oral immunotherapy (OIT) can successfully desensitize many peanut allergic subjects, but clinical tolerance diminishes over time upon discontinuation, or low dose maintenance, of peanut. Therefore, in order to improve the efficacy and sustainability of such therapy, we sought to identify biomarkers and clinical tools that can predict therapeutic outcomes and monitor treatment responses.We evaluated whether basophil activation in whole blood, and plasma levels of peanut-specific immunoglobulins, are useful biomarkers for peanut OIT.We longitudinally measured, before, during and after OIT, basophil activation in whole blood ex vivo in response to peanut stimulation, and peanut-specific IgE and IgG4, in a large, single-site, double-blind, randomized, placebo-controlled, phase 2 peanut OIT study. We compared basophil responsiveness and peanut specific immunoglobulins between those who were clinically reactive vs. tolerant to peanut oral challenges.Peanut OIT significantly decreased basophil activation, peanut-specific, Ara h 1, Ara h 2 and Ara h 3 IgEs, and sIgE/total IgE, but increased sIgG4/sIgE. Participants who became reactive to 4 g of peanut 13 weeks off active OIT exhibited higher peanut-induced basophil activation ex vivo and higher peanut-specific IgEs and sIgE/total IgE, but lower sIgG4/sIgE. Notably, participants entering the study with low basophil responsiveness were more likely to achieve treatment success. Substantial suppression of basophil activation was required to maintain long-term clinical tolerance after peanut OIT.Assessments of peanut-specific basophil activation and peanut-specific immunoglobulins can help to predict treatment outcomes, and to differentiate transient desensitization vs. sustained unresponsiveness after OIT.
View details for DOI 10.1016/j.jaci.2019.10.038
View details for PubMedID 31805311
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Sustained outcomes in oral immunotherapy for peanut allergy (POISED study): a large, randomised, double-blind, placebo-controlled, phase 2 study.
Lancet (London, England)
2019
Abstract
Dietary avoidance is recommended for peanut allergies. We evaluated the sustained effects of peanut allergy oral immunotherapy (OIT) in a randomised long-term study in adults and children.In this randomised, double-blind, placebo-controlled, phase 2 study, we enrolled participants at the Sean N Parker Center for Allergy and Asthma Research at Stanford University (Stanford, CA, USA) with peanut allergy aged 7-55 years with a positive result from a double-blind, placebo-controlled, food challenge (DBPCFC; ≤500 mg of peanut protein), a positive skin-prick test (SPT) result (≥5 mm wheal diameter above the negative control), and peanut-specific immunoglobulin (Ig)E concentration of more than 4 kU/L. Participants were randomly assigned (2·4:1·4:1) in a two-by-two block design via a computerised system to be built up and maintained on 4000 mg peanut protein through to week 104 then discontinued on peanut (peanut-0 group), to be built up and maintained on 4000 mg peanut protein through to week 104 then to ingest 300 mg peanut protein daily (peanut-300 group) for 52 weeks, or to receive oat flour (placebo group). DBPCFCs to 4000 mg peanut protein were done at baseline and weeks 104, 117, 130, 143, and 156. The pharmacist assigned treatment on the basis of a randomised computer list. Peanut or placebo (oat) flour was administered orally and participants and the study team were masked throughout by use of oat flour that was similar in look and feel to the peanut flour and nose clips, as tolerated, to mask taste. The statistician was also masked. The primary endpoint was the proportion of participants who passed DBPCFCs to a cumulative dose of 4000 mg at both 104 and 117 weeks. The primary efficacy analysis was done in the intention-to-treat population. Safety was assessed in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT02103270.Between April 15, 2014, and March 2, 2016, of 152 individuals assessed, we enrolled 120 participants, who were randomly assigned to the peanut-0 (n=60), peanut-300 (n=35), and placebo groups (n=25). 21 (35%) of peanut-0 group participants and one (4%) placebo group participant passed the 4000 mg challenge at both 104 and 117 weeks (odds ratio [OR] 12·7, 95% CI 1·8-554·8; p=0·0024). Over the entire study, the most common adverse events were mild gastrointestinal symptoms, which were seen in 90 of 120 patients (50/60 in the peanut-0 group, 29/35 in the peanut-300 group, and 11/25 in the placebo group) and skin disorders, which were seen in 50/120 patients (26/60 in the peanut-0 group, 15/35 in the peanut-300 group, and 9/25 in the placebo group). Adverse events decreased over time in all groups. Two participants in the peanut groups had serious adverse events during the 3-year study. In the peanut-0 group, in which eight (13%) of 60 participants passed DBPCFCs at week 156, higher baseline peanut-specific IgG4 to IgE ratio and lower Ara h 2 IgE and basophil activation responses were associated with sustained unresponsiveness. No treatment-related deaths occurred.Our study suggests that peanut OIT could desensitise individuals with peanut allergy to 4000 mg peanut protein but discontinuation, or even reduction to 300 mg daily, could increase the likelihood of regaining clinical reactivity to peanut. Since baseline blood tests correlated with week 117 treatment outcomes, this study might aid in optimal patient selection for this therapy.National Institute of Allergy and Infectious Diseases.
View details for DOI 10.1016/S0140-6736(19)31793-3
View details for PubMedID 31522849
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House dust mites activate nociceptor-mast cell clusters to drive type 2 skin inflammation.
Nature immunology
2019
Abstract
Allergic skin diseases, such as atopic dermatitis, are clinically characterized by severe itching and type 2 immunity-associated hypersensitivity to widely distributed allergens, including those derived from house dust mites (HDMs). Here we found that HDMs with cysteine protease activity directly activated peptidergic nociceptors, which are neuropeptide-producing nociceptive sensory neurons that express the ion channel TRPV1 and Tac1, the gene encoding the precursor for the neuropeptide substance P. Intravital imaging and genetic approaches indicated that HDM-activated nociceptors drive the development of allergic skin inflammation by inducing the degranulation of mast cells contiguous to such nociceptors, through the release of substance P and the activation of the cationic molecule receptor MRGPRB2 on mast cells. These data indicate that, after exposure to HDM allergens, activation of TRPV1+Tac1+ nociceptor-MRGPRB2+ mast cell sensory clusters represents a key early event in the development of allergic skin reactions.
View details for DOI 10.1038/s41590-019-0493-z
View details for PubMedID 31591569
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A Phase 2 Randomized Controlled Multisite Study Using Omalizumab-facilitated Rapid Desensitization to Test Continued vs Discontinued Dosing in Multifood Allergic Individuals.
EClinicalMedicine
2019; 7: 27–38
Abstract
As there is limited data on the sustainability of desensitization of multifood-oral immunotherapy (multifood-OIT), we conducted a multisite multifood-OIT study to compare the efficacy of successful desensitization with sustained dosing vs discontinued dosing after multifood-OIT.We enrolled 70 participants, aged 5-22 years with multiple food allergies confirmed by double-blind placebo-controlled food challenges (DBPCFCs). In the open-label phase of the study, all participants received omalizumab (weeks 1-16) and multi-OIT (2-5 allergens; weeks 8-30) and eligible participants (on maintenance dose of each allergen by weeks 28-29) were randomized 1:1:1 to 1 g, 300 mg, or 0 mg arms (blinded, weeks 30-36) and then tested by food challenge at week 36. Success was defined as passing 2 g food challenge to at least 2 foods in week 36.Most participants were able to reach a dose of 2 g or higher of each of 2, 3, 4, and 5 food allergens (as applicable to the participant's food allergens in OIT) in week 36 food challenges. Using an intent-to-treat analysis, we did not find evidence that a 300 mg dose was effectively different than a 1 g dose in maintaining desensitization, and both together were more effective than OIT discontinuation (0 mg dose) (85% vs 55%, P = 0.03). Fifty-five percent of the intent-to-treat participants and 69% of per protocol participants randomized to the 0 mg arm showed no objective reactivity after 6 weeks of discontinuation. Cross-desensitization was found between cashew/pistachio and walnut/pecan when only one of the foods was part of OIT. No statistically significant safety differences were found between the three arms.These results suggest that sustained desensitization after omalizumab-facilitated multi-OIT best occurs through continued maintenance OIT dosing of either 300 mg or 1 g of each food allergen as opposed to discontinuation of multi-OIT.Sean N. Parker Center for Allergy and Asthma Research at Stanford University, Jeff and MacKenzie Bezos, NIAID AADCRC U19AI104209.ClinicalTrials.gov number, NCT02626611.
View details for DOI 10.1016/j.eclinm.2018.12.006
View details for PubMedID 31193674
View details for PubMedCentralID PMC6537534
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IgE-mediated mast cell activation promotes inflammation and cartilage destruction in osteoarthritis.
eLife
2019; 8
Abstract
Osteoarthritis is characterized by articular cartilage breakdown, and emerging evidence suggests that dysregulated innate immunity is likely involved. Here, we performed proteomic, transcriptomic, and electron microscopic analyses to demonstrate that mast cells are aberrantly activated in human and murine osteoarthritic joint tissues. Using genetic models of mast cell deficiency, we demonstrate that lack of mast cells attenuates osteoarthritis in mice. Using genetic and pharmacologic approaches, we show that the IgE/FcεRI/Syk signaling axis is critical for the development of osteoarthritis. We find that mast cell-derived tryptase induces inflammation, chondrocyte apoptosis, and cartilage breakdown. Our findings demonstrate a central role for IgE-dependent mast cell activation in the pathogenesis of osteoarthritis, suggesting that targeting mast cells could provide therapeutic benefit in human osteoarthritis.This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
View details for PubMedID 31084709
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Analysis of a Large Standardized Food Challenge Data Set to Determine Predictors of Positive Outcome Across Multiple Allergens
FRONTIERS IN IMMUNOLOGY
2018; 9
View details for DOI 10.3389/fimmu.2018.02689
View details for Web of Science ID 000451447100001
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Analysis of a Large Standardized Food Challenge Data Set to Determine Predictors of Positive Outcome Across Multiple Allergens.
Frontiers in immunology
2018; 9: 2689
Abstract
Background: Double-blind placebo-controlled food challenges (DBPCFCs) remain the gold standard for the diagnosis of food allergy; however, challenges require significant time and resources and place the patient at an increased risk for severe allergic adverse events. There have been continued efforts to identify alternative diagnostic methods to replace or minimize the need for oral food challenges (OFCs) in the diagnosis of food allergy. Methods: Data was extracted for all IRB-approved, Stanford-initiated clinical protocols involving standardized screening OFCs to a cumulative dose of 500 mg protein to any of 11 food allergens in participants with elevated skin prick test (SPT) and/or specific IgE (sIgE) values to the challenged food across 7 sites. Baseline population characteristics, biomarkers, and challenge outcomes were analyzed to develop diagnostic criteria predictive of positive OFCs across multiple allergens in our multi-allergic cohorts. Results: A total of 1247 OFCs completed by 427 participants were analyzed in this cohort. Eighty-five percent of all OFCs had positive challenges. A history of atopic dermatitis and multiple food allergies were significantly associated with a higher risk of positive OFCs. The majority of food-specific SPT, sIgE, and sIgE/total IgE (tIgE) thresholds calculated from cumulative tolerated dose (CTD)-dependent receiver operator curves (ROC) had high discrimination of OFC outcome (area under the curves > 0.75). Participants with values above the thresholds were more likely to have positive challenges. Conclusions: This is the first study, to our knowledge, to not only adjust for tolerated allergen dose in predicting OFC outcome, but to also use this method to establish biomarker thresholds. The presented findings suggest that readily obtainable biomarker values and patient demographics may be of use in the prediction of OFC outcome and food allergy. In the subset of patients with SPT or sIgE values above the thresholds, values appear highly predictive of a positive OFC and true food allergy. While these values are relatively high, they may serve as an appropriate substitute for food challenges in clinical and research settings.
View details for DOI 10.3389/fimmu.2018.02689
View details for PubMedID 30538699
View details for PubMedCentralID PMC6277531
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Baseline Gastrointestinal Eosinophilia Is Common in Oral Immunotherapy Subjects With IgE-Mediated Peanut Allergy
FRONTIERS IN IMMUNOLOGY
2018; 9
View details for DOI 10.3389/fimmu.2018.02624
View details for Web of Science ID 000450901300001
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Baseline Gastrointestinal Eosinophilia Is Common in Oral Immunotherapy Subjects With IgE-Mediated Peanut Allergy.
Frontiers in immunology
2018; 9: 2624
Abstract
Rationale: Oral immunotherapy (OIT) is an emerging treatment for food allergy. While desensitization is achieved in most subjects, many experience gastrointestinal symptoms and few develop eosinophilic gastrointestinal disease. It is unclear whether these subjects have subclinical gastrointestinal eosinophilia (GE) at baseline. We aimed to evaluate the presence of GE in subjects with food allergy before peanut OIT. Methods: We performed baseline esophagogastroduodenoscopies on 21 adults before undergoing peanut OIT. Subjects completed a detailed gastrointestinal symptom questionnaire. Endoscopic findings were assessed using the Eosinophilic Esophagitis (EoE) Endoscopic Reference Score (EREFS) and biopsies were obtained from the esophagus, gastric antrum, and duodenum. Esophageal biopsies were evaluated using the EoE Histologic Scoring System. Immunohistochemical staining for eosinophil peroxidase (EPX) was also performed. Hematoxylin and eosin and EPX stains of each biopsy were assessed for eosinophil density and EPX/mm2 was quantified using automated image analysis. Results: All subjects were asymptomatic. Pre-existing esophageal eosinophilia (>5 eosinophils per high-power field [eos/hpf]) was present in five participants (24%), three (14%) of whom had >15 eos/hpf associated with mild endoscopic findings (edema, linear furrowing, or rings; median EREFS = 0, IQR 0-0.25). Some subjects also demonstrated basal cell hyperplasia, dilated intercellular spaces, and lamina propria fibrosis. Increased eosinophils were noted in the gastric antrum (>12 eos/hpf) or duodenum (>26 eos/hpf) in 9 subjects (43%). EPX/mm2 correlated strongly with eosinophil counts (r = 0.71, p < 0.0001). Conclusions: Pre-existing GE is common in adults with IgE-mediated peanut allergy. Eosinophilic inflammation (EI) in these subjects may be accompanied by mild endoscopic and histologic findings. Longitudinal data collection during OIT is ongoing.
View details for DOI 10.3389/fimmu.2018.02624
View details for PubMedID 30524424
View details for PubMedCentralID PMC6261984
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Thirdhand smoke component can exacerbate a mouse asthma model through mast cells
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2018; 142 (5): 1618-+
View details for DOI 10.1016/j.jaci.2018.04.001
View details for Web of Science ID 000449429800023
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Eliciting Dose and Safety Outcomes From a Large Dataset of Standardized Multiple Food Challenges
FRONTIERS IN IMMUNOLOGY
2018; 9
View details for DOI 10.3389/fimmu.2018.02057
View details for Web of Science ID 000445235300001
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Eliciting Dose and Safety Outcomes From a Large Dataset of Standardized Multiple Food Challenges.
Frontiers in immunology
2018; 9: 2057
Abstract
Background: Food allergy prevalence has continued to rise over the past decade. While studies have reported threshold doses for multiple foods, large-scale multi-food allergen studies are lacking. Our goal was to identify threshold dose distributions and predictors of severe reactions during blinded oral food challenges (OFCs) in multi-food allergic patients. Methods: A retrospective chart review was performed on all Stanford-initiated clinical protocols involving standardized screening OFCs to any of 11 food allergens at 7 sites. Interval-censoring survival analysis was used to calculate eliciting dose (ED) curves for each food. Changes in severity and ED were also analyzed among participants who had repeated challenges to the same food. Results: Of 428 participants, 410 (96%) had at least one positive challenge (1445 standardized OFCs with 1054 total positive challenges). Participants undergoing peanut challenges had the highest ED50 (29.9 mg), while those challenged with egg or pistachio had the lowest (7.07 or 1.7 mg, respectively). The most common adverse event was skin related (54%), followed by gastrointestinal (GI) events (33%). A history of asthma was associated with a significantly higher risk of a severe reaction (hazard ratio [HR]: 2.37, 95% confidence interval [CI]: 1.36, 4.13). Higher values of allergen-specific IgE (sIgE) and sIgE to total IgE ratio (sIgEr) were also associated with higher risk of a severe reaction (1.49 [1.19, 1.85] and 1.84 [1.30, 2.59], respectively). Participants undergoing cashew, peanut, pecan, sesame, and walnut challenges had more severe reactions as ED increased. In participants who underwent repeat challenges, the ED did not change (p = 0.66), but reactions were more severe (p = 0.02). Conclusions: Participants with a history of asthma, high sIgEr, and/or high values of sIgE were found to be at higher risk for severe reactions during food challenges. These findings may help to optimize food challenge dosing schemes in multi-food allergic, atopic patients, specifically at lower doses where the majority of reactions occur. Trials Registration Number: ClinicalTrials. gov number NCT03539692; https://clinicaltrials.gov/ct2/show/NCT03539692.
View details for DOI 10.3389/fimmu.2018.02057
View details for PubMedID 30298065
View details for PubMedCentralID PMC6160556
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Mary Hewitt Loveless, MD The origin of venom immunotherapy
ANNALS OF ALLERGY ASTHMA & IMMUNOLOGY
2018; 121 (3): 268–71
View details for DOI 10.1016/j.anal.2018.06.020
View details for Web of Science ID 000444523300004
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Development of a tool predicting severity of allergic reaction during peanut challenge
ANNALS OF ALLERGY ASTHMA & IMMUNOLOGY
2018; 121 (1): 69-+
View details for DOI 10.1016/j.anai.2018.04.020
View details for Web of Science ID 000436596100014
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Mary Hewitt Loveless, MD, and the origin of venom immunotherapy.
Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology
2018
View details for PubMedID 29964225
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Genetic and Imaging Approaches Reveal Pro-inflammatory and Immunoregulatory Roles of Mast Cells in Contact Hypersensitivity
FRONTIERS IN IMMUNOLOGY
2018; 9: 1275
Abstract
Contact hypersensitivity (CHS) is a common T cell-mediated skin disease induced by epicutaneous sensitization to haptens. Mast cells (MCs) are widely deployed in the skin and can be activated during CHS responses to secrete diverse products, including some with pro-inflammatory and anti-inflammatory functions. Conflicting results have been obtained regarding pathogenic versus protective roles of MCs in CHS, and this has been attributed in part to the limitations of certain models for studying MC functions in vivo. This review discusses recent advances in the development and analysis of mouse models to investigate the roles of MCs and MC-associated products in vivo. Notably, fluorescent avidin-based two-photon imaging approaches enable in vivo selective labeling and simultaneous tracking of MC secretory granules (e.g., during MC degranulation) and MC gene activation by real-time longitudinal intravital microscopy in living mice. The combination of such genetic and imaging tools has shed new light on the controversial role played by MCs in mouse models of CHS. On the one hand, they can amplify CHS responses of mild severity while, on the other hand, can limit the inflammation and tissue injury associated with more severe or chronic models, in part by representing an initial source of the anti-inflammatory cytokine IL-10.
View details for PubMedID 29922295
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Imaging FITC-dextran as a Reporter for Regulated Exocytosis
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
2018
Abstract
Regulated exocytosis is a process by which cargo, which is stored in secretory granules (SGs), is released in response to a secretory trigger. Regulated exocytosis is fundamental for intercellular communication and is a key mechanism for the secretion of neurotransmitters, hormones, inflammatory mediators, and other compounds, by a variety of cells. At least three distinct mechanisms are known for regulated exocytosis: full exocytosis, where a single SG fully fuses with the plasma membrane, kiss-and-run exocytosis, where a single SG transiently fuses with the plasma membrane, and compound exocytosis, where several SGs fuse with each other, prior to or after SG fusion with the plasma membrane. The type of regulated exocytosis undertaken by a cell is often dictated by the type of secretory trigger. However, in many cells, a single secretory trigger can activate multiple modes of regulated exocytosis simultaneously. Despite their abundance and importance across cell types and species, the mechanisms that determine the different modes of secretion are largely unresolved. One of the main challenges in investigating the different modes of regulated exocytosis, is the difficulty in distinguishing between them as well as exploring them separately. Here we describe the use of fluorescein isothiocyanate (FITC)-dextran as an exocytosis reporter, and live cell imaging, to differentiate between the different pathways of regulated exocytosis, focusing on compound exocytosis, based on the robustness and duration of the exocytic events.
View details for PubMedID 29985342
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Effect of Dietary Fiber and Metabolites on Mast Cell Activation and Mast Cell-Associated Diseases
FRONTIERS IN IMMUNOLOGY
2018; 9
View details for DOI 10.3389/fimmu.2018.01067
View details for Web of Science ID 000433351700001
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Effect of Dietary Fiber and Metabolites on Mast Cell Activation and Mast Cell-Associated Diseases.
Frontiers in immunology
2018; 9: 1067
Abstract
Many mast cell-associated diseases, including allergies and asthma, have seen a strong increase in prevalence during the past decades, especially in Western(ized) countries. It has been suggested that a Western diet may contribute to the prevalence and manifestation of allergies and asthma through reduced intake of dietary fiber and the subsequent production of their metabolites. Indeed, dietary fiber and its metabolites have been shown to positively influence the development of immune disorders via changes in microbiota composition and the regulation of B- and T-cell activation. However, the effects of these dietary components on the activation of mast cells, key effector cells of the inflammatory response in allergies and asthma, remain poorly characterized. Due to their location in the gut and vascularized tissues, mast cells are exposed to high concentrations of dietary fiber and/or its metabolites. Here, we provide a focused overview of current findings regarding the direct effects of dietary fiber and its various metabolites on the regulation of mast cell activity and the pathophysiology of mast cell-associated diseases.
View details for DOI 10.3389/fimmu.2018.01067
View details for PubMedID 29910798
View details for PubMedCentralID PMC5992428
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Isotype-specific agglutination-PCR (ISAP): Asensitive and multiplex method for measuring allergen-specific IgE.
The Journal of allergy and clinical immunology
2018; 141 (5): 1901
View details for PubMedID 29248495
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Isotype-specific agglutination-PCR (ISAP): A sensitive and multiplex method for measuring allergen-specific IgE
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2018; 141 (5): 1901-+
View details for DOI 10.1016/j.jaci.2017.11.021
View details for Web of Science ID 000432148200038
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Development of a tool predicting severity of allergic reaction during peanut challenge.
Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology
2018
Abstract
BACKGROUND: Reliable prognostic markers for predicting severity of allergic reactions during oral food challenges (OFC) have not been established.OBJECTIVE: We sought to develop a predictive algorithm of a food challenge severity score (CSS) to identify those at higher risk for severe reactions to a standardized peanut OFC.METHODS: Medical history and allergy tests were obtained for 120 peanut-allergic participants who underwent double-blind, placebo-controlled food challenges (DBPCFCs). Reactions were assigned a CSS between 1 to 6 based on cumulative tolerated dose and a "severity clinical indicator." Demographic characteristics, clinical features, peanut component IgE values, and a basophil activation marker were considered in a multi-step analysis to derive a flexible decision rule to understand risk during peanut of OFC.RESULTS: 18.3% participants had a severe reaction (CSS >4). The decision rule identified the following three variables (in order of importance) as predictors of reaction severity: ratio of %CD63hi stimulation with peanut to %CD63hi anti-IgE (CD63 ratio), history of exercise-induced asthma, and forced expiratory volume in 1 sec/forced vital capacity (FEV1/FVC) ratio. The CD63 ratio alone was a strong predictor of CSS (p<0.001).CONCLUSION: The CSS is a novel tool that combines dose thresholds and allergic reactions to understand risks associated with peanut OFCs. Lab-values (CD63 ratio), along with clinical variables (exercise-induced asthma and FEV1/FVC ratio) contribute to the predictive ability of the severity of reaction to peanut OFC. Further testing of this decision rule is needed in a larger external data source before it can be considered outside of research settings.
View details for PubMedID 29709643
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Epigenetic Changes in Immune Cells Following Successful Desensitization with Multi-Food Allergen Oral Immunotherapy
SPRINGER/PLENUM PUBLISHERS. 2018: 358–59
View details for Web of Science ID 000431311600075
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Mast cells as sources of cytokines, chemokines, and growth factors
IMMUNOLOGICAL REVIEWS
2018; 282 (1): 121–50
Abstract
Mast cells are hematopoietic cells that reside in virtually all vascularized tissues and that represent potential sources of a wide variety of biologically active secreted products, including diverse cytokines and growth factors. There is strong evidence for important non-redundant roles of mast cells in many types of innate or adaptive immune responses, including making important contributions to immediate and chronic IgE-associated allergic disorders and enhancing host resistance to certain venoms and parasites. However, mast cells have been proposed to influence many other biological processes, including responses to bacteria and virus, angiogenesis, wound healing, fibrosis, autoimmune and metabolic disorders, and cancer. The potential functions of mast cells in many of these settings is thought to reflect their ability to secrete, upon appropriate activation by a range of immune or non-immune stimuli, a broad spectrum of cytokines (including many chemokines) and growth factors, with potential autocrine, paracrine, local, and systemic effects. In this review, we summarize the evidence indicating which cytokines and growth factors can be produced by various populations of rodent and human mast cells in response to particular immune or non-immune stimuli, and comment on the proven or potential roles of such mast cell products in health and disease.
View details for PubMedID 29431212
View details for PubMedCentralID PMC5813811
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Anti-IgE treatment with oral immunotherapy in multifood allergic participants: a double-blind, randomised, controlled trial
LANCET GASTROENTEROLOGY & HEPATOLOGY
2018; 3 (2): 85–94
Abstract
Despite progress in single food oral immunotherapy, there is little evidence concerning the safety and efficacy of treating individuals with multiple food (multifood) allergies. We did a pilot study testing whether anti-IgE (omalizumab) combined with multifood oral immunotherapy benefited multifood allergic patients.We did a blinded, phase 2 clinical trial at Stanford University. We enrolled participants, aged 4-15 years, with multifood allergies validated by double-blind, placebo-controlled food challenges to their offending foods. Inclusion criteria included a positive skin prick test of 6 mm or more (wheal diameter, above the negative control), a food-specific serum IgE concentration of more than 4 kU/L for each food, or both, and a positive double-blind, placebo-controlled food challenge at 500 mg or less of food protein. Exclusion criteria included eosinophilic oesophagitis and severe asthma. Participants were randomised (3:1) with a block size of four, to receive multifood oral immunotherapy to two to five foods, together with omalizumab (n=36) or placebo (n=12). 12 individuals who fulfilled the same inclusion and exclusion criteria were included as controls. These individuals were not randomised and received neither omalizumab nor oral immunotherapy. Omalizumab or placebo was administered subcutaneously for 16 weeks, with oral immunotherapy starting at week 8, and was stopped 20 weeks before the exit double-blind, placebo-controlled food challenge at week 36. The primary endpoint was the proportion of participants who passed double-blind, placebo-controlled food challenges to at least two of their offending foods. This completed trial is registered with ClinicalTrials.gov, number NCT02643862.Between March 25, 2015, and Aug 18, 2016, 165 participants were assessed for eligibility, of whom 84 did not meet the inclusion criteria and 21 declined to participate. We enrolled and randomised 48 eligible participants and the remaining 12 patients were included as nonrandomised, untreated controls. At week 36, a significantly greater proportion of the omalizumab-treated (30 [83%] of 36) versus placebo (four [33%] of 12) participants passed double-blind, placebo-controlled food challenges to 2 g protein for two or more of their offending foods (odds ratio 10·0, 95% CI 1·8-58·3, p=0·0044). All participants completed the study. There were no serious or severe (grade 3 or worse) adverse events. Participants in the omalizumab group had a significantly lower median per-participant percentage of oral immunotherapy doses associated with any adverse events (27% vs 68%; p=0·0082). The most common adverse events in both groups were gastrointestinal events.In multifood allergic patients, omalizumab improves the efficacy of multifood oral immunotherapy and enables safe and rapid desensitisation.US National Institutes of Health (NIH).
View details for PubMedID 29242014
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Human mast cells as antigen-presenting cells: When is this role important in vivo?
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2018; 141 (1): 92–93
View details for PubMedID 28624609
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Thirdhand smoke component can exacerbate a mouse asthma model through mast cells.
The Journal of allergy and clinical immunology
2018
Abstract
Thirdhand smoke (THS) represents the accumulation of secondhand smoke on indoor surfaces and in dust, which, over time, can become more toxic than secondhand smoke. Although it is well known that children of smokers are at increased risk for asthma or asthma exacerbation if the disease is already present, how exposure to THS can influence the development or exacerbation of asthma remains unknown.We investigated whether epicutaneous exposure to an important component of THS, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), can influence asthma pathology in a mouse model elicited by means of repeated intranasal challenge with cockroach antigen (CRA).Wild-type mice, α7 nicotinic acetylcholine receptor (nAChR)- or mast cell (MC)-deficient mice, and mice with MCs that lacked α7 nAChRs or were the host's sole source of α7 nAChRs were subjected to epicutaneous NNK exposure, intranasal CRA challenge, or both, and the severity of features of asthma pathology, including airway hyperreactivity, airway inflammation, and airway remodeling, was assessed.We found that α7 nAChRs were required to observe adverse effects of epicutaneous NNK exposure on multiple features of CRA-induced asthma pathology. Moreover, MC expression of α7 nAChRs contributed significantly to the ability of epicutaneous NNK exposure to exacerbate airway hyperreactivity to methacholine, airway inflammation, and airway remodeling in this model.Our results show that skin exposure to NNK, a component of THS, can exacerbate multiple features of a CRA-induced model of asthma in mice and define MCs as key contributors to these adverse effects of NNK.
View details for PubMedID 29678746
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Food allergy and omics.
The Journal of allergy and clinical immunology
2018; 141 (1): 20–29
Abstract
Food allergy (FA) prevalence has been increasing over the last few decades and is now a global health concern. Current diagnostic methods for FA result in a high number of false-positive results, and the standard of care is either allergen avoidance or use of epinephrine on accidental exposure, although currently with no other approved treatments. The increasing prevalence of FA, lack of robust biomarkers, and inadequate treatments warrants further research into the mechanism underlying food allergies. Recent technological advances have made it possible to move beyond traditional biological techniques to more sophisticated high-throughput approaches. These technologies have created the burgeoning field of omics sciences, which permit a more systematic investigation of biological problems. Omics sciences, such as genomics, epigenomics, transcriptomics, proteomics, metabolomics, microbiomics, and exposomics, have enabled the construction of regulatory networks and biological pathway models. Parallel advances in bioinformatics and computational techniques have enabled the integration, analysis, and interpretation of these exponentially growing data sets and opens the possibility of personalized or precision medicine for FA.
View details for PubMedID 29307411
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Proposed Terminology and Classification of Pre-Malignant Neoplastic Conditions: A Consensus Proposal.
EBioMedicine
2017; 26: 17-24
Abstract
Cancer evolution is a step-wise non-linear process that may start early in life or later in adulthood, and includes pre-malignant (indolent) and malignant phases. Early somatic changes may not be detectable or are found by chance in apparently healthy individuals. The same lesions may be detected in pre-malignant clonal conditions. In some patients, these lesions may never become relevant clinically whereas in others, they act together with additional pro-oncogenic hits and thereby contribute to the formation of an overt malignancy. Although some pre-malignant stages of a malignancy have been characterized, no global system to define and to classify these conditions is available. To discuss open issues related to pre-malignant phases of neoplastic disorders, a working conference was organized in Vienna in August 2015. The outcomes of this conference are summarized herein and include a basic proposal for a nomenclature and classification of pre-malignant conditions. This proposal should assist in the communication among patients, physicians and scientists, which is critical as genome-sequencing will soon be offered widely for early cancer-detection.
View details for DOI 10.1016/j.ebiom.2017.11.024
View details for PubMedID 29203377
View details for PubMedCentralID PMC5832623
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Proposed Terminology and Classification of Pre-Malignant Neoplastic Conditions: A Consensus Proposal
EBIOMEDICINE
2017; 26: 17–24
View details for DOI 10.1016/j.ebiom.2017.11.024
View details for Web of Science ID 000425875200010
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Rab5 is critical for SNAP23 regulated granule-granule fusion during compound exocytosis
SCIENTIFIC REPORTS
2017; 7: 15315
Abstract
Compound exocytosis is considered the most massive mode of exocytosis, during which the membranes of secretory granules (SGs) fuse with each other to form a channel through which the entire contents of their granules is released. The underlying mechanisms of compound exocytosis remain largely unresolved. Here we show that the small GTPase Rab5, a known regulator of endocytosis, is pivotal for compound exocytosis in mast cells. Silencing of Rab5 shifts receptor-triggered secretion from a compound to a full exocytosis mode, in which SGs individually fuse with the plasma membrane. Moreover, we show that Rab5 is essential for FcεRI-triggered association of the SNARE protein SNAP23 with the SGs. Direct evidence is provided for SNAP23 involvement in homotypic SG fusion that occurs in the activated cells. Finally, we show that this fusion event is prevented by inhibition of the IKKβ2 kinase, however, neither a phosphorylation-deficient nor a phosphomimetic mutant of SNAP23 can mediate homotypic SG fusion in triggered cells. Taken together our findings identify Rab5 as a heretofore-unrecognized regulator of compound exocytosis that is essential for SNAP23-mediated granule-granule fusion. Our results also implicate phosphorylation cycles in controlling SNAP23 SNARE function in homotypic SG fusion.
View details for PubMedID 29127297
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Targeting of Immune Cells by Dual TLR2/7 Ligands Suppresses Features of Allergic Th2 Immune Responses in Mice.
Journal of immunology research
2017; 2017: 7983217
Abstract
TLR ligands can promote Th1-biased immune responses, mimicking potent stimuli of viruses and bacteria.To investigate the adjuvant properties of dual TLR2/7 ligands compared to those of the mixture of both single ligands.Dual TLR2/7 ligands: CL401, CL413, and CL531, including CL264 (TLR7-ligand) and Pam2CysK4 (TLR2-ligand), were used. Immune-modulatory capacity of the dual ligands with the individual ligands alone or as a mixture in mouse BMmDCs, BMmDC:TC cocultures, or BMCMCs was compared and assessed in naïve mice and in a mouse model of OVA-induced intestinal allergy.CL413 and CL531 induced BMmDC-derived IL-10 secretion, suppressed rOVA-induced IL-5 secretion from OVA-specific DO11.10 CD4+ TCs, and induced proinflammatory cytokine secretion in vivo. In contrast, CL401 induced considerably less IL-10 secretion and led to IL-17A production in BMmDC:TC cocultures, but not BMCMC IL-6 secretion, or IL-6 or TNF-α production in vivo. No immune-modulating effects were observed with single ligands. All dual TLR2/7 ligands suppressed DNP-induced IgE-and-Ag-specific mast cell degranulation. Compared to vaccination with OVA, vaccination with the mixture CL531 and OVA, significantly suppressed OVA-specific IgE production in the intestinal allergy model.Based on beneficial immune-modulating properties, CL413 and CL531 may have utility as potential adjuvants for allergy treatment.
View details for DOI 10.1155/2017/7983217
View details for PubMedID 29204451
View details for PubMedCentralID PMC5674512
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The tyrosine kinase inhibitor imatinib mesylate suppresses uric acid crystal-induced acute gouty arthritis in mice
PLOS ONE
2017; 12 (10): e0185704
Abstract
Gouty arthritis is caused by the deposition of monosodium urate (MSU) crystals in joints. Despite many treatment options for gout, there is a substantial need for alternative treatments for patients unresponsive to current therapies. Tyrosine kinase inhibitors have demonstrated therapeutic benefit in experimental models of antibody-dependent arthritis and in rheumatoid arthritis in humans, but to date, the potential effects of such inhibitors on gouty arthritis has not been evaluated. Here we demonstrate that treatment with the tyrosine kinase inhibitor imatinib mesylate (imatinib) can suppress inflammation induced by injection of MSU crystals into subcutaneous air pouches or into the ankle joint of wild type mice. Moreover, imatinib treatment also largely abolished the lower levels of inflammation which developed in IL-1R1-/- or KitW-sh/W-sh mice, indicating that this drug can inhibit IL-1-independent pathways, as well as mast cell-independent pathways, contributing to pathology in this model. Imatinib treatment not only prevented ankle swelling and synovial inflammation when administered before MSU crystals but also diminished these features when administrated after the injection of MSU crystals, a therapeutic protocol more closely mimicking the clinical situation in which treatment occurs after the development of an acute gout flare. Finally, we also assessed the efficiency of local intra-articular injections of imatinib-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles in this model of acute gout. Treatment with low doses of this long-acting imatinib:PLGA formulation was able to reduce ankle swelling in a therapeutic protocol. Altogether, these results raise the possibility that tyrosine kinase inhibitors might have utility in the treatment of acute gout in humans.
View details for PubMedID 28982129
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A new fluorescent-avidin-based method for quantifying basophil activation in whole blood
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2017; 140 (4): 1202-+
View details for PubMedID 28606590
View details for PubMedCentralID PMC5632583
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Imaging protective mast cells in living mice during severe contact hypersensitivity.
JCI insight
2017; 2 (9)
Abstract
Contact hypersensitivity (CHS) is a common skin disease induced by epicutaneous sensitization to haptens. Conflicting results have been obtained regarding pathogenic versus protective roles of mast cells (MCs) in CHS, and this has been attributed in part to the limitations of certain models for studying MC functions in vivo. Here we describe a fluorescent imaging approach that enables in vivo selective labeling and tracking of MC secretory granules by real-time intravital 2-photon microscopy in living mice, and permits the identification of such MCs as a potential source of cytokines in different disease models. We show using this method that dermal MCs release their granules progressively into the surrounding microenvironment, but also represent an initial source of the antiinflammatory cytokine IL-10, during the early phase of severe CHS reactions. Finally, using 3 different types of MC-deficient mice, as well as mice in which IL-10 is ablated specifically in MCs, we show that IL-10 production by MCs can significantly limit the inflammation and tissue pathology observed in severe CHS reactions.
View details for DOI 10.1172/jci.insight.92900
View details for PubMedID 28469089
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Differences in the Importance of Mast Cells, Basophils, IgE, and IgG versus That of CD4(+) T Cells and ILC2 Cells in Primary and Secondary Immunity to Strongyloides venezuelensis
INFECTION AND IMMUNITY
2017; 85 (5)
Abstract
There is evidence that mast cells, basophils and IgE can contribute to immune responses to parasites, however, the relative importance of these effector elements in parasite immunity is not fully understood. Previous work in Il3-deficient and c-kit mutant Kit(W/W-v) mice indicated that interleukin-3 and c-Kit contribute to expulsion of the intestinal nematode Strongyloides venezuelensis (S.v.) during primary infection. Our findings in mast cell-deficient Kit(W-sh/W-sh) mice and two types of mast cell-deficient mice that have normal c-kit: "Hello Kitty" and MasTRECK mice, confirmed prior work in Kit(W/W-v) mice suggesting that mast cells play an important role in S.v. egg clearance in primary infections. We also assessed a possible contribution of basophils in immune responses to S.v By immunohistochemistry, we found that numbers of basophils and mast cells, were markedly increased in the jejunal mucosa during primary infections with S.v Studies in basophil-deficient Mcpt8(DTR) mice revealed a small but significant contribution of basophils to S.v. egg clearance in primary infections. Studies in mice deficient in various components of immune responses showed that CD4(+) T cells and ILC2 cells, IgG, FcRγ, and to a lesser extent, IgE and FcϵRI, contribute to effective immunity in primary S.v infections. These findings support the conclusion that the hierarchy of importance of immune effector mechanisms in primary S.v. infection is: CD4(+) T cells/ILC2 cells, IgG and FcRγ>mast cells>IgE and FcϵRI>basophils. By contrast, in secondary S.v infection, our evidence indicates that CD4(+) T cells are critical but mast cells, antibodies, and basophils have little or no non-redundant roles.
View details for DOI 10.1128/IAI.00053-17
View details for Web of Science ID 000399882200009
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Neutrophil myeloperoxidase diminishes the toxic effects and mortality induced by lipopolysaccharide
JOURNAL OF EXPERIMENTAL MEDICINE
2017; 214 (5): 1249-1258
Abstract
Neutrophils have crucial antimicrobial functions but are also thought to contribute to tissue injury upon exposure to bacterial products, such as lipopolysaccharide (LPS). To study the role of neutrophils in LPS-induced endotoxemia, we developed a new mouse model, PMN(DTR) mice, in which injection of diphtheria toxin induces selective neutrophil ablation. Using this model, we found, surprisingly, that neutrophils serve to protect the host from LPS-induced lethal inflammation. This protective role was observed in conventional and germ-free animal facilities, indicating that it does not depend on a particular microbiological environment. Blockade or genetic deletion of myeloperoxidase (MPO), a key neutrophil enzyme, significantly increased mortality after LPS challenge, and adoptive transfer experiments confirmed that neutrophil-derived MPO contributes importantly to protection from endotoxemia. Our findings imply that, in addition to their well-established antimicrobial properties, neutrophils can contribute to optimal host protection by limiting the extent of endotoxin-induced inflammation in an MPO-dependent manner.
View details for DOI 10.1084/jem.20161238
View details for Web of Science ID 000400379300006
View details for PubMedID 28385925
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Association of Clinical Reactivity with Sensitization to Allergen Components in Multifood-Allergic Children.
journal of allergy and clinical immunology. In practice
2017
Abstract
Thirty percent of children with food allergies have multiple simultaneous allergies; however, the features of these multiple allergies are not well characterized serologically or clinically.We comprehensively evaluated 60 multifood-allergic patients by measuring serum IgE to key allergen components, evaluating clinical histories and medication use, performing skin tests, and conducting double-blind, placebo-controlled food challenges (DBPCFCs).Sixty participants with multiple food allergies were characterized by clinical history, DBPCFCs, total IgE, specific IgE, and component-resolved diagnostics (IgE and IgG4) data. The food allergens tested were almond, egg, milk, sesame, peanut, pecan, walnut, hazelnut, cashew, pistachio, soy, and wheat.Our data demonstrate that of the reactions observed during a graded DBPCFC, gastrointestinal reactions occurred more often in boys than in girls, as well as in individuals with high levels of IgE to 2S albumins from cashew, walnut, and hazelnut. Certain food allergies often occurred concomitantly in individuals (ie, cashew/pistachio and walnut/pecan/hazelnut). IgE testing to components further corroborated serological relationships between and among these clustered food allergies.Associations of certain food allergies were shown by DBPCFC outcomes as well as by correlations in IgE reactivity to structurally related food allergen components. Each of these criteria independently demonstrated a significant association between allergies to cashew and pistachio, as well as among allergies to walnut, pecan, and hazelnut.
View details for DOI 10.1016/j.jaip.2017.01.016
View details for PubMedID 28351786
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Decoupling the Functional Pleiotropy of Stem Cell Factor by Tuning c-Kit Signaling
CELL
2017; 168 (6): 1041-?
Abstract
Most secreted growth factors and cytokines are functionally pleiotropic because their receptors are expressed on diverse cell types. While important for normal mammalian physiology, pleiotropy limits the efficacy of cytokines and growth factors as therapeutics. Stem cell factor (SCF) is a growth factor that acts through the c-Kit receptor tyrosine kinase to elicit hematopoietic progenitor expansion but can be toxic when administered in vivo because it concurrently activates mast cells. We engineered a mechanism-based SCF partial agonist that impaired c-Kit dimerization, truncating downstream signaling amplitude. This SCF variant elicited biased activation of hematopoietic progenitors over mast cells in vitro and in vivo. Mouse models of SCF-mediated anaphylaxis, radioprotection, and hematopoietic expansion revealed that this SCF partial agonist retained therapeutic efficacy while exhibiting virtually no anaphylactic off-target effects. The approach of biasing cell activation by tuning signaling thresholds and outputs has applications to many dimeric receptor-ligand systems.
View details for DOI 10.1016/j.cell.2017.02.011
View details for Web of Science ID 000396287900012
View details for PubMedID 28283060
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.
Infection and immunity
2017
Abstract
There is evidence that mast cells, basophils and IgE can contribute to immune responses to parasites, however, the relative importance of these effector elements in parasite immunity is not fully understood. Previous work in Il3-deficient and c-kit mutant Kit(W/W-v) mice indicated that interleukin-3 and c-Kit contribute to expulsion of the intestinal nematode Strongyloides venezuelensis (S.v.) during primary infection. Our findings in mast cell-deficient Kit(W-sh/W-sh) mice and two types of mast cell-deficient mice that have normal c-kit: "Hello Kitty" and MasTRECK mice, confirmed prior work in Kit(W/W-v) mice suggesting that mast cells play an important role in S.v. egg clearance in primary infections. We also assessed a possible contribution of basophils in immune responses to S.v By immunohistochemistry, we found that numbers of basophils and mast cells, were markedly increased in the jejunal mucosa during primary infections with S.v Studies in basophil-deficient Mcpt8(DTR) mice revealed a small but significant contribution of basophils to S.v. egg clearance in primary infections. Studies in mice deficient in various components of immune responses showed that CD4(+) T cells and ILC2 cells, IgG, FcRγ, and to a lesser extent, IgE and FcϵRI, contribute to effective immunity in primary S.v infections. These findings support the conclusion that the hierarchy of importance of immune effector mechanisms in primary S.v. infection is: CD4(+) T cells/ILC2 cells, IgG and FcRγ>mast cells>IgE and FcϵRI>basophils. By contrast, in secondary S.v infection, our evidence indicates that CD4(+) T cells are critical but mast cells, antibodies, and basophils have little or no non-redundant roles.
View details for DOI 10.1128/IAI.00053-17
View details for PubMedID 28264908
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Advances in the Classification and Treatment of Mastocytosis: Current Status and Outlook toward the Future.
Cancer research
2017
Abstract
Mastocytosis is a term used to denote a heterogeneous group of conditions defined by the expansion and accumulation of clonal (neoplastic) tissue mast cells in various organs. The classification of the World Health Organization (WHO) divides the disease into cutaneous mastocytosis, systemic mastocytosis, and localized mast cell tumors. On the basis of histomorphologic criteria, clinical parameters, and organ involvement, systemic mastocytosis is further divided into indolent systemic mastocytosis and advanced systemic mastocytosis variants, including aggressive systemic mastocytosis and mast cell leukemia. The clinical impact and prognostic value of this classification has been confirmed in numerous studies, and its basic concept remains valid. However, refinements have recently been proposed by the consensus group, the WHO, and the European Competence Network on Mastocytosis. In addition, new treatment options are available for patients with advanced systemic mastocytosis, including allogeneic hematopoietic stem cell transplantation and multikinase inhibitors directed against KIT D816V and other key signaling molecules. Our current article provides an overview of recent advances in the field of mastocytosis, with emphasis on classification, prognostication, and emerging new treatment options in advanced systemic mastocytosis. Cancer Res; 77(6); 1261-70. ©2017 AACR.
View details for DOI 10.1158/0008-5472.CAN-16-2234
View details for PubMedID 28254862
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Assessing basophil activation by using flow cytometry and mass cytometry in blood stored 24 hours before analysis
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2017; 139 (3): 889-?
Abstract
Basophil activation tests (BATs) have promise for research and for clinical monitoring of patients with allergies. However, BAT protocols vary in blood anticoagulant used and temperature and time of storage before testing, complicating comparisons of results from various studies.We attempted to establish a BAT protocol that would permit analysis of blood within 24 hours of obtaining the sample.Blood from 46 healthy donors and 120 patients with peanut allergy was collected into EDTA or heparin tubes, and samples were stored at 4°C or room temperature for 4 or 24 hours before performing BATs.Stimulation with anti-IgE or IL-3 resulted in strong upregulation of basophil CD203c in samples collected in EDTA or heparin, stored at 4°C, and analyzed 24 hours after sample collection. However, a CD63(hi) population of basophils was not observed in any conditions in EDTA-treated samples unless exogenous calcium/magnesium was added at the time of anti-IgE stimulation. By contrast, blood samples collected in heparin tubes were adequate for quantification of upregulation of basophil CD203c and identification of a population of CD63(hi) basophils, irrespective of whether the specimens were analyzed by means of conventional flow cytometry or cytometry by time-of-flight mass spectrometry, and such tests could be performed after blood was stored for 24 hours at 4°C.BATs to measure upregulation of basophil CD203c and induction of a CD63(hi) basophil population can be conducted with blood obtained in heparin tubes and stored at 4°C for 24 hours.
View details for DOI 10.1016/j.jaci.2016.04.060
View details for Web of Science ID 000397295800022
View details for PubMedCentralID PMC5237629
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Pathways of immediate hypothermia and leukocyte infiltration in an adjuvant-free mouse model of anaphylaxis
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2017; 139 (2): 584-?
Abstract
Conflicting results have been obtained regarding the roles of Fc receptors and effector cells in models of active systemic anaphylaxis (ASA). In part, this might reflect the choice of adjuvant used during sensitization because various adjuvants might differentially influence the production of particular antibody isotypes.We developed an "adjuvant-free" mouse model of ASA and assessed the contributions of components of the "classical" and "alternative" pathways in this model.Mice were sensitized intraperitoneally with ovalbumin at weekly intervals for 6 weeks and challenged intraperitoneally with ovalbumin 2 weeks later.Wild-type animals had immediate hypothermia and late-phase intraperitoneal inflammation in this model. These features were reduced in mice lacking the IgE receptor FcεRI, the IgG receptor FcγRIII or the common γ-chain FcRγ. FcγRIV blockade resulted in a partial reduction of inflammation without any effect on hypothermia. Depletion of monocytes/macrophages with clodronate liposomes significantly reduced the hypothermia response. By contrast, depletion of neutrophils or basophils had no significant effects in this ASA model. Both the hypothermia and inflammation were dependent on platelet-activating factor and histamine and were reduced in 2 types of mast cell (MC)-deficient mice. Finally, engraftment of MC-deficient mice with bone marrow-derived cultured MCs significantly exacerbated the hypothermia response and restored inflammation to levels similar to those observed in wild-type mice.Components of the classical and alternative pathways contribute to anaphylaxis in this adjuvant-free model, with key roles for MCs and monocytes/macrophages.
View details for DOI 10.1016/j.jaci.2016.05.047
View details for Web of Science ID 000397002400024
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Assessing basophil activation by flow cytometry and mass cytometry in blood stored 24 hours before analysis
MOSBY-ELSEVIER. 2017: AB124
View details for DOI 10.1016/j.jaci.2016.12.402
View details for Web of Science ID 000401699800293
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Characterization of multifood allergic children based on clinical and serological data
MOSBY-ELSEVIER. 2017: AB140
View details for DOI 10.1016/j.jaci.2016.12.460
View details for Web of Science ID 000401699800349
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Immune monitoring for precision medicine in allergy and asthma.
Current opinion in immunology
2017; 48: 82–91
Abstract
'Precision Medicine' embodies the analyses of extensive data collected from patients and their environments to identify and apply patient-specific prophylactic strategies and medical treatments to improve clinical outcomes and healthcare cost-effectiveness. Many new methods have been developed for evaluating the activity of the human immune system. Such 'immune monitoring' approaches are now being used in studies of allergy and asthma in the hope of identifying better correlates of disease status, predictors of therapeutic outcomes, and potential side-effects of treatment. Together with analyses of family histories, genetic and other biometric data, and measurements of exposures to environmental and other risk factors for developing or exacerbating disease, immune monitoring approaches promise to enable 'Precision Medicine' for allergic diseases and asthma.
View details for DOI 10.1016/j.coi.2017.08.007
View details for PubMedID 28889067
View details for PubMedCentralID PMC5743231
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Final Comments: A Roadmap to Safety
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 379-387
View details for Web of Science ID 000468283200012
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Management in the Health Care Setting
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 227-275
View details for Web of Science ID 000468283200008
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Management of Packaged Foods
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 277-332
View details for Web of Science ID 000468283200009
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Managing Food Allergies in Retail, Food Service, Schools, Higher Education, and Travel Settings
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 333-364
View details for Web of Science ID 000468283200010
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Definitions
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 39-58
View details for Web of Science ID 000468283200004
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Prevalence
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 59-96
View details for Web of Science ID 000468283200005
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Potential Genetic and Environmental Determinants of Food Allergy Risk and Possible Prevention Strategies
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 139-226
View details for Web of Science ID 000468283200007
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Research Needs
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 365-377
View details for Web of Science ID 000468283200011
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Finding a Path to Safety in Food Allergy Assessment of the Global Burden, Causes, Prevention, Management, and Public Policy Introduction
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 19-37
View details for Web of Science ID 000468283200003
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Assessments, Diagnostic Testing, Disease Monitoring, and Prognosis
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 97-137
View details for Web of Science ID 000468283200006
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Finding a Path to Safety in Food Allergy Assessment of the Global Burden, Causes, Prevention, Management, and Public Policy Summary
FINDING A PATH TO SAFETY IN FOOD ALLERGY: ASSESSMENT OF THE GLOBAL BURDEN, CAUSES, PREVENTION, MANAGEMENT, AND PUBLIC POLICY
2017: 1-17
View details for Web of Science ID 000468283200002
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Mast Cells and IgE can Enhance Survival During Innate and Acquired Host Responses to Venoms.
Transactions of the American Clinical and Climatological Association
2017; 128: 193–221
Abstract
Mast cells and immunoglobulin E (IgE) antibodies are thought to promote health by contributing to host responses to certain parasites, but other beneficial functions have remained obscure. Venoms provoke innate inflammatory responses and pathology reflecting the activities of the contained toxins. Venoms also can induce allergic sensitization and development of venom-specific IgE antibodies, which can predispose some subjects to exhibit anaphylaxis upon subsequent exposure to the relevant venom. We found that innate functions of mast cells, including degradation of venom toxins by mast cell-derived proteases, enhanced survival in mice injected with venoms from the honeybee, two species of scorpion, three species of poisonous snakes, or the Gila monster. We also found that mice injected with sub-lethal amounts of honeybee or Russell's viper venom exhibited enhanced survival after subsequent challenge with potentially lethal amounts of that venom, and that IgE antibodies, FcepsilonRI, and probably mast cells contributed to such acquired resistance.
View details for PubMedID 28790503
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The pathophysiology of anaphylaxis.
The Journal of allergy and clinical immunology
2017; 140 (2): 335–48
Abstract
Anaphylaxis is a severe systemic hypersensitivity reaction that is rapid in onset; characterized by life-threatening airway, breathing, and/or circulatory problems; and usually associated with skin and mucosal changes. Because it can be triggered in some persons by minute amounts of antigen (eg, certain foods or single insect stings), anaphylaxis can be considered the most aberrant example of an imbalance between the cost and benefit of an immune response. This review will describe current understanding of the immunopathogenesis and pathophysiology of anaphylaxis, focusing on the roles of IgE and IgG antibodies, immune effector cells, and mediators thought to contribute to examples of the disorder. Evidence from studies of anaphylaxis in human subjects will be discussed, as well as insights gained from analyses of animal models, including mice genetically deficient in the antibodies, antibody receptors, effector cells, or mediators implicated in anaphylaxis and mice that have been "humanized" for some of these elements. We also review possible host factors that might influence the occurrence or severity of anaphylaxis. Finally, we will speculate about anaphylaxis from an evolutionary perspective and argue that, in the context of severe envenomation by arthropods or reptiles, anaphylaxis might even provide a survival advantage.
View details for PubMedID 28780941
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Reply.
The Journal of allergy and clinical immunology
2017; 139 (6): 2029–31
View details for PubMedID 28410741
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Mast Cells and KIT as Potential Therapeutic Targets in Severe Asthma.
The New England journal of medicine
2017; 376 (20): 1983–84
View details for PubMedID 28514622
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Targeting of Immune Cells by Dual TLR2/7 Ligands Suppresses Features of Allergic Th2 Immune Responses in Mice
JOURNAL OF IMMUNOLOGY RESEARCH
2017
View details for DOI 10.1155/2017/7983217
View details for Web of Science ID 000414576700001
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IgG subclasses determine pathways of anaphylaxis in mice.
journal of allergy and clinical immunology
2017; 139 (1): 269-280 e7
Abstract
Animal models have demonstrated that allergen-specific IgG confers sensitivity to systemic anaphylaxis that relies on IgG Fc receptors (FcγRs). Mouse IgG2a and IgG2b bind activating FcγRI, FcγRIII, and FcγRIV and inhibitory FcγRIIB; mouse IgG1 binds only FcγRIII and FcγRIIB. Although these interactions are of strikingly different affinities, these 3 IgG subclasses have been shown to enable induction of systemic anaphylaxis.We sought to determine which pathways control the induction of IgG1-, IgG2a-, and IgG2b-dependent passive systemic anaphylaxis.Mice were sensitized with IgG1, IgG2a, or IgG2b anti-trinitrophenyl mAbs and challenged with trinitrophenyl-BSA intravenously to induce systemic anaphylaxis that was monitored by using rectal temperature. Anaphylaxis was evaluated in mice deficient for FcγRs injected with mediator antagonists or in which basophils, monocytes/macrophages, or neutrophils had been depleted. FcγR expression was evaluated on these cells before and after anaphylaxis.Activating FcγRIII is the receptor primarily responsible for all 3 models of anaphylaxis, and subsequent downregulation of this receptor was observed. These models differentially relied on histamine release and the contribution of mast cells, basophils, macrophages, and neutrophils. Strikingly, basophil contribution and histamine predominance in mice with IgG1- and IgG2b-induced anaphylaxis correlated with the ability of inhibitory FcγRIIB to negatively regulate these models of anaphylaxis.We propose that the differential expression of inhibitory FcγRIIB on myeloid cells and its differential binding of IgG subclasses controls the contributions of mast cells, basophils, neutrophils, and macrophages to IgG subclass-dependent anaphylaxis. Collectively, our results unravel novel complexities in the involvement and regulation of cell populations in IgG-dependent reactions in vivo.
View details for DOI 10.1016/j.jaci.2016.03.028
View details for PubMedID 27246523
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IgG subclasses determine pathways of anaphylaxis in mice
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2017; 139 (1): 269-?
Abstract
Animal models have demonstrated that allergen-specific IgG confers sensitivity to systemic anaphylaxis that relies on IgG Fc receptors (FcγRs). Mouse IgG2a and IgG2b bind activating FcγRI, FcγRIII, and FcγRIV and inhibitory FcγRIIB; mouse IgG1 binds only FcγRIII and FcγRIIB. Although these interactions are of strikingly different affinities, these 3 IgG subclasses have been shown to enable induction of systemic anaphylaxis.We sought to determine which pathways control the induction of IgG1-, IgG2a-, and IgG2b-dependent passive systemic anaphylaxis.Mice were sensitized with IgG1, IgG2a, or IgG2b anti-trinitrophenyl mAbs and challenged with trinitrophenyl-BSA intravenously to induce systemic anaphylaxis that was monitored by using rectal temperature. Anaphylaxis was evaluated in mice deficient for FcγRs injected with mediator antagonists or in which basophils, monocytes/macrophages, or neutrophils had been depleted. FcγR expression was evaluated on these cells before and after anaphylaxis.Activating FcγRIII is the receptor primarily responsible for all 3 models of anaphylaxis, and subsequent downregulation of this receptor was observed. These models differentially relied on histamine release and the contribution of mast cells, basophils, macrophages, and neutrophils. Strikingly, basophil contribution and histamine predominance in mice with IgG1- and IgG2b-induced anaphylaxis correlated with the ability of inhibitory FcγRIIB to negatively regulate these models of anaphylaxis.We propose that the differential expression of inhibitory FcγRIIB on myeloid cells and its differential binding of IgG subclasses controls the contributions of mast cells, basophils, neutrophils, and macrophages to IgG subclass-dependent anaphylaxis. Collectively, our results unravel novel complexities in the involvement and regulation of cell populations in IgG-dependent reactions in vivo.
View details for DOI 10.1016/j.jaci.2016.03.028
View details for Web of Science ID 000393996800028
View details for PubMedCentralID PMC5081282
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A TNFRSF14-Fc epsilon RI-mast cell pathway contributes to development of multiple features of asthma pathology in mice
NATURE COMMUNICATIONS
2016; 7
Abstract
Asthma has multiple features, including airway hyperreactivity, inflammation and remodelling. The TNF superfamily member TNFSF14 (LIGHT), via interactions with the receptor TNFRSF14 (HVEM), can support TH2 cell generation and longevity and promote airway remodelling in mouse models of asthma, but the mechanisms by which TNFSF14 functions in this setting are incompletely understood. Here we find that mouse and human mast cells (MCs) express TNFRSF14 and that TNFSF14:TNFRSF14 interactions can enhance IgE-mediated MC signalling and mediator production. In mouse models of asthma, TNFRSF14 blockade with a neutralizing antibody administered after antigen sensitization, or genetic deletion of Tnfrsf14, diminishes plasma levels of antigen-specific IgG1 and IgE antibodies, airway hyperreactivity, airway inflammation and airway remodelling. Finally, by analysing two types of genetically MC-deficient mice after engrafting MCs that either do or do not express TNFRSF14, we show that TNFRSF14 expression on MCs significantly contributes to the development of multiple features of asthma pathology.
View details for DOI 10.1038/ncomms13696
View details for Web of Science ID 000389853400001
View details for PubMedID 27982078
View details for PubMedCentralID PMC5171877
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Evidence that beta 7 Integrin Regulates Hematopoietic Stem Cell Homing and Engraftment Through Interaction with MAdCAM-1
STEM CELLS AND DEVELOPMENT
2016; 25 (1): 18-26
Abstract
α4β7 integrin is a cell adhesion receptor that is crucial for the migration of hematopoietic progenitors and mature effector cells in the periphery, but its role in adult hematopoiesis is controversial. We identified a subset of hematopoietic stem cells (HSCs) in the bone marrow (BM) that expressed β7 integrin. These β7(+) HSCs were capable of multilineage, long-term reconstitution and had an inherent competitive advantage over β7(-) HSCs. On the other hand, HSCs that lacked β7 integrin (β7KO) had reduced engraftment potential. Interestingly, quantitative RT-PCR and flow cytometry revealed that β7KO HSCs expressed lower levels of the chemokine receptor CXCR4. Accordingly, β7KO HSCs exhibited impaired migration abilities in vitro and BM homing capabilities in vivo. Lethal irradiation induced expression of the α4β7 integrin ligand-mucosal addressin cell adhesion molecule-1 (MAdCAM-1) on BM endothelial cells. Moreover, blocking MAdCAM-1 reduced the homing of HSCs and impaired the survival of recipient mice. Altogether, these data indicate that β7 integrin, when expressed by HSCs, interacted with its endothelial ligand MAdCAM-1 in the BM microenvironment, thereby promoting HSC homing and engraftment.
View details for DOI 10.1089/scd.2014.0551
View details for PubMedID 26422691
View details for PubMedCentralID PMC4692116
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Guanine nucleotide exchange factor RABGEF1 regulates keratinocyte-intrinsic signaling to maintain skin homeostasis.
journal of clinical investigation
2016
Abstract
Epidermal keratinocytes form a structural and immune barrier that is essential for skin homeostasis. However, the mechanisms that regulate epidermal barrier function are incompletely understood. Here we have found that keratinocyte-specific deletion of the gene encoding RAB guanine nucleotide exchange factor 1 (RABGEF1, also known as RABEX-5) severely impairs epidermal barrier function in mice and induces an allergic cutaneous and systemic phenotype. RABGEF1-deficient keratinocytes exhibited aberrant activation of the intrinsic IL-1R/MYD88/NF-κB signaling pathway and MYD88-dependent abnormalities in expression of structural proteins that contribute to skin barrier function. Moreover, ablation of MYD88 signaling in RABGEF1-deficient keratinocytes or deletion of Il1r1 restored skin homeostasis and prevented development of skin inflammation. We further demonstrated that epidermal RABGEF1 expression is reduced in skin lesions of humans diagnosed with either atopic dermatitis or allergic contact dermatitis as well as in an inducible mouse model of allergic dermatitis. Our findings reveal a key role for RABGEF1 in dampening keratinocyte-intrinsic MYD88 signaling and sustaining epidermal barrier function in mice, and suggest that dysregulation of RABGEF1 expression may contribute to epidermal barrier dysfunction in allergic skin disorders in mice and humans. Thus, RABGEF1-mediated regulation of IL-1R/MYD88 signaling might represent a potential therapeutic target.
View details for DOI 10.1172/JCI86359
View details for PubMedID 27820702
View details for PubMedCentralID PMC5127679
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The Nedd4-2/Ndfip1 axis is a negative regulator of IgE-mediated mast cell activation.
Nature communications
2016; 7: 13198-?
Abstract
Cross-linkage of the high-affinity immunoglobulin E (IgE) receptor (FcɛRI) on mast cells by antigen ligation has a critical role in the pathology of IgE-dependent allergic disorders, such as anaphylaxis and asthma. Restraint of intracellular signal transduction pathways that promote release of mast cell-derived pro-inflammatory mediators is necessary to dampen activation and restore homoeostasis. Here we show that the ligase Nedd4-2 and the adaptor Ndfip1 (Nedd4 family interacting protein 1) limit the intensity and duration of IgE-FcɛRI-induced positive signal transduction by ubiquitinating phosphorylated Syk, a tyrosine kinase that is indispensable for downstream FcɛRI signalosome activity. Importantly, loss of Nedd4-2 or Ndfip1 in mast cells results in exacerbated and prolonged IgE-mediated cutaneous anaphylaxis in vivo. Our findings reveal an important negative regulatory function for Nedd4-2 and Ndfip1 in IgE-dependent mast cell activity.
View details for DOI 10.1038/ncomms13198
View details for PubMedID 27786273
View details for PubMedCentralID PMC5095291
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Different activation signals induce distinct mast cell degranulation strategies
JOURNAL OF CLINICAL INVESTIGATION
2016; 126 (10): 3981-3998
Abstract
Mast cells (MCs) influence intercellular communication during inflammation by secreting cytoplasmic granules that contain diverse mediators. Here, we have demonstrated that MCs decode different activation stimuli into spatially and temporally distinct patterns of granule secretion. Certain signals, including substance P, the complement anaphylatoxins C3a and C5a, and endothelin 1, induced human MCs rapidly to secrete small and relatively spherical granule structures, a pattern consistent with the secretion of individual granules. Conversely, activating MCs with anti-IgE increased the time partition between signaling and secretion, which was associated with a period of sustained elevation of intracellular calcium and formation of larger and more heterogeneously shaped granule structures that underwent prolonged exteriorization. Pharmacological inhibition of IKK-β during IgE-dependent stimulation strongly reduced the time partition between signaling and secretion, inhibited SNAP23/STX4 complex formation, and switched the degranulation pattern into one that resembled degranulation induced by substance P. IgE-dependent and substance P-dependent activation in vivo also induced different patterns of mouse MC degranulation that were associated with distinct local and systemic pathophysiological responses. These findings show that cytoplasmic granule secretion from MCs that occurs in response to different activating stimuli can exhibit distinct dynamics and features that are associated with distinct patterns of MC-dependent inflammation.
View details for DOI 10.1172/JCI85538
View details for Web of Science ID 000384703300034
View details for PubMedID 27643442
View details for PubMedCentralID PMC5096814
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IgE and mast cells in host defense against parasites and venoms.
Seminars in immunopathology
2016; 38 (5): 581-603
Abstract
IgE-dependent mast cell activation is a major effector mechanism underlying the pathology associated with allergic disorders. The most dramatic of these IgE-associated disorders is the fatal anaphylaxis which can occur in some people who have developed IgE antibodies to otherwise innocuous antigens, such as those contained in certain foods and medicines. Why would such a highly "maladaptive" immune response develop in evolution and be retained to the present day? Host defense against parasites has long been considered the only beneficial function that might be conferred by IgE and mast cells. However, recent studies have provided evidence that, in addition to participating in host resistance to certain parasites, mast cells and IgE are critical components of innate (mast cells) and adaptive (mast cells and IgE) immune responses that can enhance host defense against the toxicity of certain arthropod and animal venoms, including enhancing the survival of mice injected with such venoms. Yet, in some people, developing IgE antibodies to insect or snake venoms puts them at risk for having a potentially fatal anaphylactic reaction upon subsequent exposure to such venoms. Delineating the mechanisms underlying beneficial versus detrimental innate and adaptive immune responses associated with mast cell activation and IgE is likely to enhance our ability to identify potential therapeutic targets in such settings, not only for reducing the pathology associated with allergic disorders but perhaps also for enhancing immune protection against pathogens and animal venoms.
View details for DOI 10.1007/s00281-016-0565-1
View details for PubMedID 27225312
View details for PubMedCentralID PMC5010491
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The Nedd4-2-Ndfip1 axis is essential to curtail mast cell-dependent IgE-mediated anaphylaxis in vivo
WILEY-BLACKWELL. 2016: 16–17
View details for Web of Science ID 000383610400034
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Why do we have mast cells and IgE? Roles in enhancing host defenses against venoms
WILEY-BLACKWELL. 2016: 753
View details for Web of Science ID 000383610401707
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Evidence that IgE-associated immune responses can increase or lower resistance to venoms
WILEY-BLACKWELL. 2016: 110
View details for Web of Science ID 000383679800220
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Pathways of anaphylaxis in an adjuvant-free mouse model
WILEY-BLACKWELL. 2016: 290
View details for Web of Science ID 000383679801435
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Pathways of immediate hypothermia and leukocyte infiltration in an adjuvant-free mouse model of anaphylaxis.
journal of allergy and clinical immunology
2016
Abstract
Conflicting results have been obtained regarding the roles of Fc receptors and effector cells in models of active systemic anaphylaxis (ASA). In part, this might reflect the choice of adjuvant used during sensitization because various adjuvants might differentially influence the production of particular antibody isotypes.We developed an "adjuvant-free" mouse model of ASA and assessed the contributions of components of the "classical" and "alternative" pathways in this model.Mice were sensitized intraperitoneally with ovalbumin at weekly intervals for 6 weeks and challenged intraperitoneally with ovalbumin 2 weeks later.Wild-type animals had immediate hypothermia and late-phase intraperitoneal inflammation in this model. These features were reduced in mice lacking the IgE receptor FcεRI, the IgG receptor FcγRIII or the common γ-chain FcRγ. FcγRIV blockade resulted in a partial reduction of inflammation without any effect on hypothermia. Depletion of monocytes/macrophages with clodronate liposomes significantly reduced the hypothermia response. By contrast, depletion of neutrophils or basophils had no significant effects in this ASA model. Both the hypothermia and inflammation were dependent on platelet-activating factor and histamine and were reduced in 2 types of mast cell (MC)-deficient mice. Finally, engraftment of MC-deficient mice with bone marrow-derived cultured MCs significantly exacerbated the hypothermia response and restored inflammation to levels similar to those observed in wild-type mice.Components of the classical and alternative pathways contribute to anaphylaxis in this adjuvant-free model, with key roles for MCs and monocytes/macrophages.
View details for DOI 10.1016/j.jaci.2016.05.047
View details for PubMedID 27555460
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Assessing basophil activation by using flow cytometry and mass cytometry in blood stored 24 hours before analysis.
journal of allergy and clinical immunology
2016
Abstract
Basophil activation tests (BATs) have promise for research and for clinical monitoring of patients with allergies. However, BAT protocols vary in blood anticoagulant used and temperature and time of storage before testing, complicating comparisons of results from various studies.We attempted to establish a BAT protocol that would permit analysis of blood within 24 hours of obtaining the sample.Blood from 46 healthy donors and 120 patients with peanut allergy was collected into EDTA or heparin tubes, and samples were stored at 4°C or room temperature for 4 or 24 hours before performing BATs.Stimulation with anti-IgE or IL-3 resulted in strong upregulation of basophil CD203c in samples collected in EDTA or heparin, stored at 4°C, and analyzed 24 hours after sample collection. However, a CD63(hi) population of basophils was not observed in any conditions in EDTA-treated samples unless exogenous calcium/magnesium was added at the time of anti-IgE stimulation. By contrast, blood samples collected in heparin tubes were adequate for quantification of upregulation of basophil CD203c and identification of a population of CD63(hi) basophils, irrespective of whether the specimens were analyzed by means of conventional flow cytometry or cytometry by time-of-flight mass spectrometry, and such tests could be performed after blood was stored for 24 hours at 4°C.BATs to measure upregulation of basophil CD203c and induction of a CD63(hi) basophil population can be conducted with blood obtained in heparin tubes and stored at 4°C for 24 hours.
View details for DOI 10.1016/j.jaci.2016.04.060
View details for PubMedID 27527263
View details for PubMedCentralID PMC5237629
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Toward precision medicine and health: Opportunities and challenges in allergic diseases
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2016; 137 (5): 1289-1300
Abstract
Precision medicine (also called personalized, stratified, or P4 medicine) can be defined as the tailoring of preventive measures and medical treatments to the characteristics of each patient to obtain the best clinical outcome for each person while ideally also enhancing the cost-effectiveness of such interventions for patients and society. Clearly, the best clinical outcome for allergic diseases is not to get them in the first place. To emphasize the importance of disease prevention, a critical component of precision medicine can be referred to as precision health, which is defined herein as the use of all available information pertaining to specific subjects (including family history, individual genetic and other biometric information, and exposures to risk factors for developing or exacerbating disease), as well as features of their environments, to sustain and enhance health and prevent the development of disease. In this article I will provide a personal perspective on how the precision health-precision medicine approach can be applied to the related goals of preventing the development of allergic disorders and providing the most effective diagnosis, disease monitoring, and care for those with these prevalent diseases. I will also mention some of the existing and potential challenges to achieving these ambitious goals.
View details for DOI 10.1016/j.jaci.2016.03.006
View details for Web of Science ID 000376180200001
View details for PubMedID 27155026
View details for PubMedCentralID PMC4872702
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Molecular and cellular mechanisms of food allergy and food tolerance.
journal of allergy and clinical immunology
2016; 137 (4): 984-997
Abstract
Ingestion of innocuous antigens, including food proteins, normally results in local and systemic immune nonresponsiveness in a process termed oral tolerance. Oral tolerance to food proteins is likely to be intimately linked to mechanisms that are responsible for gastrointestinal tolerance to large numbers of commensal microbes. Here we review our current understanding of the immune mechanisms responsible for oral tolerance and how perturbations in these mechanisms might promote the loss of oral tolerance and development of food allergies. Roles for the commensal microbiome in promoting oral tolerance and the association of intestinal dysbiosis with food allergy are discussed. Growing evidence supports cutaneous sensitization to food antigens as one possible mechanism leading to the failure to develop or loss of oral tolerance. A goal of immunotherapy for food allergies is to induce sustained desensitization or even true long-term oral tolerance to food allergens through mechanisms that might in part overlap with those associated with the development of natural oral tolerance.
View details for DOI 10.1016/j.jaci.2016.02.004
View details for PubMedID 27059726
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Successful immunotherapy induces previously unidentified allergen-specific CD4+ T-cell subsets.
Proceedings of the National Academy of Sciences of the United States of America
2016; 113 (9): E1286-95
Abstract
Allergen immunotherapy can desensitize even subjects with potentially lethal allergies, but the changes induced in T cells that underpin successful immunotherapy remain poorly understood. In a cohort of peanut-allergic participants, we used allergen-specific T-cell sorting and single-cell gene expression to trace the transcriptional "roadmap" of individual CD4+ T cells throughout immunotherapy. We found that successful immunotherapy induces allergen-specific CD4+ T cells to expand and shift toward an "anergic" Th2 T-cell phenotype largely absent in both pretreatment participants and healthy controls. These findings show that sustained success, even after immunotherapy is withdrawn, is associated with the induction, expansion, and maintenance of immunotherapy-specific memory and naive T-cell phenotypes as early as 3 mo into immunotherapy. These results suggest an approach for immune monitoring participants undergoing immunotherapy to predict the success of future treatment and could have implications for immunotherapy targets in other diseases like cancer, autoimmune disease, and transplantation.
View details for DOI 10.1073/pnas.1520180113
View details for PubMedID 26811452
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The Mast Cell-IgE Paradox From Homeostasis to Anaphylaxis
AMERICAN JOURNAL OF PATHOLOGY
2016; 186 (2): 212-224
Abstract
Mast cells and IgE are so inextricably linked to the pathology of allergic disorders, including fatal anaphylaxis, that it can be difficult to think of them in other contexts. Surely, we do not have mast cells and IgE so that we can eat a peanut and die! It is thought that mast cells and IgE and basophils (circulating granulocytes, whose functions partially overlap with those of mast cells) can contribute to host defense as components of adaptive T helper cell type 2 immune responses to helminths, ticks, and certain other parasites. Accordingly, it was suggested that allergies are misdirected type 2 immune responses in which IgE antibodies are produced against any of a broad variety of apparently harmless antigens. However, components of animal venoms also can sensitize individuals to develop severe IgE-associated allergic reactions, including fatal anaphylaxis, on subsequent venom exposure. Here, I describe evidence that mast cells can enhance innate host resistance to reptile or arthropod venoms during responses to an initial exposure to such venoms and that acquired type 2 immune responses, IgE antibodies, the high-affinity IgE receptor FcεRI, and mast cells can contribute toward acquired resistance in mice to the lethal effects of honeybee or Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against noxious substances.
View details for DOI 10.1016/j.ajpath.2015.07.025
View details for Web of Science ID 000368969900001
View details for PubMedID 26776074
View details for PubMedCentralID PMC4729269
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Development of Multiple Features of Antigen-Induced Asthma Pathology in a New Strain of Mast Cell Deficient BALB/c-Kit(W-Sh/W-Sh) Mice
MOSBY-ELSEVIER. 2016: AB406
View details for DOI 10.1016/j.jaci.2015.12.1260
View details for Web of Science ID 000375005405036
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Severity of Reactions to Oral Peanut Challenges in Children and Adults
MOSBY-ELSEVIER. 2016: AB134
View details for DOI 10.1016/j.jaci.2015.12.573
View details for Web of Science ID 000375005402134
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Trends in Adverse Reactions Requiring Epinephrine in the Build-up Phase of Oral Immunotherapy
MOSBY-ELSEVIER. 2016: AB131
View details for DOI 10.1016/j.jaci.2015.12.563
View details for Web of Science ID 000375005402124
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Neutrophils are not required for resolution of acute gouty arthritis in mice.
Nature medicine
2016; 22 (12): 1382–84
View details for PubMedID 27923029
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Computational Pathology A Path Ahead
ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE
2016; 140 (1): 41-50
Abstract
We define the scope and needs within the new discipline of computational pathology, a discipline critical to the future of both the practice of pathology and, more broadly, medical practice in general.To define the scope and needs of computational pathology.A meeting was convened in Boston, Massachusetts, in July 2014 prior to the annual Association of Pathology Chairs meeting, and it was attended by a variety of pathologists, including individuals highly invested in pathology informatics as well as chairs of pathology departments.The meeting made recommendations to promote computational pathology, including clearly defining the field and articulating its value propositions; asserting that the value propositions for health care systems must include means to incorporate robust computational approaches to implement data-driven methods that aid in guiding individual and population health care; leveraging computational pathology as a center for data interpretation in modern health care systems; stating that realizing the value proposition will require working with institutional administrations, other departments, and pathology colleagues; declaring that a robust pipeline should be fostered that trains and develops future computational pathologists, for those with both pathology and nonpathology backgrounds; and deciding that computational pathology should serve as a hub for data-related research in health care systems. The dissemination of these recommendations to pathology and bioinformatics departments should help facilitate the development of computational pathology.
View details for DOI 10.5858/arpa.2015-0093-SA
View details for PubMedID 26098131
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Mast cells and IgE in defense against venoms: Possible "good side" of allergy?
Allergology international : official journal of the Japanese Society of Allergology
2016; 65 (1): 3-15
Abstract
Physicians think of mast cells and IgE primarily in the context of allergic disorders, including fatal anaphylaxis. This 'bad side' of mast cells and IgE is so well accepted that it can be difficult to think of them in other contexts, particularly those in which they may have beneficial functions. However, there is evidence that mast cells and IgE, as well as basophils (circulating granulocytes whose functions partially overlap with those of mast cells), can contribute to host defense as components of adaptive type 2 immune responses to helminths, ticks and certain other parasites. Accordingly, allergies often are conceptualized as "misdirected" type 2 immune responses, in which IgE antibodies are produced against any of a diverse group of apparently harmless antigens, as well as against components of animal venoms. Indeed, certain unfortunate patients who have become sensitized to venoms develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. In this review, we will describe evidence that mast cells can enhance innate resistance to reptile or arthropod venoms during a first exposure to such venoms. We also will discuss findings indicating that, in mice which survive an initial encounter with venom, acquired type 2 immune responses, IgE antibodies, the high affinity IgE receptor (FcɛRI), and mast cells can contribute to acquired resistance to the lethal effects of both honeybee venom and Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against venoms and perhaps other noxious substances.
View details for DOI 10.1016/j.alit.2015.09.002
View details for PubMedID 26666482
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Mast cells and IgE in defense against venoms: Possible "good side" of allergy?
ALLERGOLOGY INTERNATIONAL
2016; 65 (1): 3-15
Abstract
Physicians think of mast cells and IgE primarily in the context of allergic disorders, including fatal anaphylaxis. This 'bad side' of mast cells and IgE is so well accepted that it can be difficult to think of them in other contexts, particularly those in which they may have beneficial functions. However, there is evidence that mast cells and IgE, as well as basophils (circulating granulocytes whose functions partially overlap with those of mast cells), can contribute to host defense as components of adaptive type 2 immune responses to helminths, ticks and certain other parasites. Accordingly, allergies often are conceptualized as "misdirected" type 2 immune responses, in which IgE antibodies are produced against any of a diverse group of apparently harmless antigens, as well as against components of animal venoms. Indeed, certain unfortunate patients who have become sensitized to venoms develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. In this review, we will describe evidence that mast cells can enhance innate resistance to reptile or arthropod venoms during a first exposure to such venoms. We also will discuss findings indicating that, in mice which survive an initial encounter with venom, acquired type 2 immune responses, IgE antibodies, the high affinity IgE receptor (FcɛRI), and mast cells can contribute to acquired resistance to the lethal effects of both honeybee venom and Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against venoms and perhaps other noxious substances.
View details for DOI 10.1016/j.alit.2015.09.002
View details for Web of Science ID 000367238600002
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IgE antibodies, FceRIa, and IgE-mediated local anaphylaxis can limit snake venom toxicity.
journal of allergy and clinical immunology
2016; 137 (1): 246-257 e11
Abstract
Type 2 cytokine-related immune responses associated with development of antigen-specific IgE antibodies can contribute to pathology in patients with allergic diseases and to fatal anaphylaxis. However, recent findings in mice indicate that IgE also can enhance defense against honeybee venom.We tested whether IgE antibodies, IgE-dependent effector mechanisms, and a local anaphylactic reaction to an unrelated antigen can enhance defense against Russell viper venom (RVV) and determined whether such responses can be influenced by immunization protocol or mouse strain.We compared the resistance of RVV-immunized wild-type, IgE-deficient, and Fcer1a-deficient mice after injection of a potentially lethal dose of RVV.A single prior exposure to RVV enhanced the ability of wild-type mice, but not mice lacking IgE or functional FcεRI, to survive challenge with a potentially lethal amount of RVV. Moreover, IgE-dependent local passive cutaneous anaphylaxis in response to challenge with an antigen not naturally present in RVV significantly enhanced resistance to the venom. Finally, we observed different effects on resistance to RVV or honeybee venom in BALB/c versus C57BL/6 mice that had received a second exposure to that venom before challenge with a high dose of that venom.These observations illustrate the potential benefit of IgE-dependent effector mechanisms in acquired host defense against venoms. The extent to which type 2 immune responses against venoms can decrease pathology associated with envenomation seems to be influenced by the type of venom, the frequency of venom exposure, and the genetic background of the host.
View details for DOI 10.1016/j.jaci.2015.08.005
View details for PubMedID 26410782
View details for PubMedCentralID PMC4715494
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The adherens junctions control susceptibility to Staphylococcus aureus a-toxin.
Proceedings of the National Academy of Sciences of the United States of America
2015; 112 (46): 14337-14342
Abstract
Staphylococcus aureus is both a transient skin colonizer and a formidable human pathogen, ranking among the leading causes of skin and soft tissue infections as well as severe pneumonia. The secreted bacterial α-toxin is essential for S. aureus virulence in these epithelial diseases. To discover host cellular factors required for α-toxin cytotoxicity, we conducted a genetic screen using mutagenized haploid human cells. Our screen identified a cytoplasmic member of the adherens junctions, plekstrin-homology domain containing protein 7 (PLEKHA7), as the second most significantly enriched gene after the known α-toxin receptor, a disintegrin and metalloprotease 10 (ADAM10). Here we report a new, unexpected role for PLEKHA7 and several components of cellular adherens junctions in controlling susceptibility to S. aureus α-toxin. We find that despite being injured by α-toxin pore formation, PLEKHA7 knockout cells recover after intoxication. By infecting PLEKHA7(-/-) mice with methicillin-resistant S. aureus USA300 LAC strain, we demonstrate that this junctional protein controls disease severity in both skin infection and lethal S. aureus pneumonia. Our results suggest that adherens junctions actively control cellular responses to a potent pore-forming bacterial toxin and identify PLEKHA7 as a potential nonessential host target to reduce S. aureus virulence during epithelial infections.
View details for DOI 10.1073/pnas.1510265112
View details for PubMedID 26489655
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MPLA shows attenuated pro-inflammatory properties and diminished capacity to activate mast cells in comparison with LPS.
Allergy
2015; 70 (10): 1259-1268
Abstract
Monophosphoryl lipid A (MPLA), a nontoxic TLR4 ligand derived from lipopolysaccharide (LPS), is used clinically as an adjuvant in cancer, hepatitis, and malaria vaccines and in allergen-specific immunotherapy. Nevertheless, its cell-activating effects have not been analyzed in a comprehensive direct comparison including a wide range of different immune cells. Therefore, the objective of this study was the side-by-side comparison of the immune-modulating properties of MPLA and LPS on different immune cells.Immune-activating properties of MPLA and LPS were compared in human monocytes and mast cells (MCs), a mouse endotoxin shock model (ESM), and mouse bone marrow (BM)-derived myeloid dendritic cells (mDCs), T cells (TCs), B cells, and MCs.In a mouse in vivo ESM and a human ex vivo monocyte activation test (MAT), MPLA induced the same cytokine secretion pattern as LPS (ESM: IL-6, IL-12, TNF-α; MAT: IL-1β, IL-6, TNF-α), albeit at lower levels. Mouse mDCs and ex vivo isolated B cells stimulated with MPLA required a higher threshold to induce TRIF-dependent cytokine secretion (IL-1β, IL-6, IL-10, and TNF-α) than did LPS-stimulated cells. In mDC:DO11.10 CD4 TC cocultures, stimulation with MPLA, but not with LPS, resulted in enhanced OVA-specific IL-4 and IL-5 secretion from DO11.10 CD4 TCs. Unexpectedly, in both human and mouse MCs, MPLA, unlike LPS, did not elicit secretion of pro-inflammatory cytokines.Compared to LPS, MPLA induced a qualitatively similar, but less potent pro-inflammatory immune response, but was unable to activate human or mouse MCs.
View details for DOI 10.1111/all.12675
View details for PubMedID 26081583
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Testing the 'toxin hypothesis of allergy': mast cells, IgE, and innate and acquired immune responses to venoms
CURRENT OPINION IN IMMUNOLOGY
2015; 36: 80-87
Abstract
Work in mice indicates that innate functions of mast cells, particularly degradation of venom toxins by mast cell-derived proteases, can enhance resistance to certain arthropod or reptile venoms. Recent reports indicate that acquired Th2 immune responses associated with the production of IgE antibodies, induced by Russell's viper venom or honeybee venom, or by a component of honeybee venom, bee venom phospholipase 2 (bvPLA2), can increase the resistance of mice to challenge with potentially lethal doses of either of the venoms or bvPLA2. These findings support the conclusion that, in contrast to the detrimental effects associated with allergic type 2 (Th2) immune responses, mast cells and IgE-dependent immune responses to venoms can contribute to innate and adaptive resistance to venom-induced pathology and mortality.
View details for DOI 10.1016/j.coi.2015.07.001
View details for Web of Science ID 000363070000014
View details for PubMedID 26210895
View details for PubMedCentralID PMC4593748
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An Interleukin-33-Mast Cell-Interleukin-2 Axis Suppresses Papain-Induced Allergic Inflammation by Promoting Regulatory T Cell Numbers
IMMUNITY
2015; 43 (1): 175-186
Abstract
House dust mite-derived proteases contribute to allergic disorders in part by disrupting epithelial barrier function. Interleukin-33 (IL-33), produced by lung cells after exposure to protease allergens, can induce innate-type airway eosinophilia by activating natural helper (NH) cells, a member of group 2 innate lymphoid cells (ILC2), to secrete Th2 type-cytokines. Because IL-33 also can induce mast cells (MCs) to secrete Th2 type-cytokines, MCs are thought to cooperate with NH cells in enhancing protease or IL-33-mediated innate-type airway eosinophilia. However, we found that MC-deficient Kit(W-sh/W-sh) mice exhibited exacerbated protease-induced lung inflammation associated with reduced numbers of regulatory T (Treg) cells. Moreover, IL-2 produced by IL-33-stimulated MCs promoted expansion of numbers of Treg cells, thereby suppressing development of papain- or IL-33-induced airway eosinophilia. We have thus identified a unique anti-inflammatory pathway that can limit induction of innate-type allergic airway inflammation mediated by NH cells.
View details for DOI 10.1016/j.immuni.2015.06.021
View details for Web of Science ID 000360101100019
View details for PubMedCentralID PMC4533925
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An Interleukin-33-Mast Cell-Interleukin-2 Axis Suppresses Papain-Induced Allergic Inflammation by Promoting Regulatory T Cell Numbers.
Immunity
2015; 43 (1): 175-86
Abstract
House dust mite-derived proteases contribute to allergic disorders in part by disrupting epithelial barrier function. Interleukin-33 (IL-33), produced by lung cells after exposure to protease allergens, can induce innate-type airway eosinophilia by activating natural helper (NH) cells, a member of group 2 innate lymphoid cells (ILC2), to secrete Th2 type-cytokines. Because IL-33 also can induce mast cells (MCs) to secrete Th2 type-cytokines, MCs are thought to cooperate with NH cells in enhancing protease or IL-33-mediated innate-type airway eosinophilia. However, we found that MC-deficient Kit(W-sh/W-sh) mice exhibited exacerbated protease-induced lung inflammation associated with reduced numbers of regulatory T (Treg) cells. Moreover, IL-2 produced by IL-33-stimulated MCs promoted expansion of numbers of Treg cells, thereby suppressing development of papain- or IL-33-induced airway eosinophilia. We have thus identified a unique anti-inflammatory pathway that can limit induction of innate-type allergic airway inflammation mediated by NH cells.
View details for DOI 10.1016/j.immuni.2015.06.021
View details for PubMedID 26200013
View details for PubMedCentralID PMC4533925
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Genomics in the clinic: ethical and policy challenges in clinical next-generation sequencing programs at early adopter USA institutions.
Personalized medicine
2015; 12 (3): 269-282
Abstract
Next-generation sequencing (NGS) technologies are poised to revolutionize clinical diagnosis and treatment, but raise significant ethical and policy challenges. This review examines NGS program challenges through a synthesis of published literature, website and conference presentation content, and interviews at early-adopting institutions in the USA. Institutions are proactively addressing policy challenges related to the management and technical aspects of program development. However, ethical challenges related to patient-related aspects have not been fully addressed. These complex challenges present opportunities to develop comprehensive and standardized regulations across programs. Understanding the strengths, weaknesses and current practices of evolving NGS program approaches are important considerations for institutions developing NGS services, policymakers regulating or funding NGS programs and physicians and patients considering NGS services.
View details for DOI 10.2217/pme.14.88
View details for PubMedID 29771644
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Potential effector and immunoregulatory functions of mast cells in mucosal immunity
MUCOSAL IMMUNOLOGY
2015; 8 (3): 444-463
Abstract
Mast cells (MCs) are cells of hematopoietic origin that normally reside in mucosal tissues, often near epithelial cells, glands, smooth muscle cells, and nerves. Best known for their contributions to pathology during IgE-associated disorders such as food allergy, asthma, and anaphylaxis, MCs are also thought to mediate IgE-associated effector functions during certain parasite infections. However, various MC populations also can be activated to express functional programs--such as secreting preformed and/or newly synthesized biologically active products--in response to encounters with products derived from diverse pathogens, other host cells (including leukocytes and structural cells), damaged tissue, or the activation of the complement or coagulation systems, as well as by signals derived from the external environment (including animal toxins, plant products, and physical agents). In this review, we will discuss evidence suggesting that MCs can perform diverse effector and immunoregulatory roles that contribute to homeostasis or pathology in mucosal tissues.
View details for DOI 10.1038/mi.2014.131
View details for Web of Science ID 000354085700002
View details for PubMedID 25669149
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Approaches for analyzing the roles of mast cells and their proteases in vivo.
Advances in immunology
2015; 126: 45-127
Abstract
The roles of mast cells in health and disease remain incompletely understood. While the evidence that mast cells are critical effector cells in IgE-dependent anaphylaxis and other acute IgE-mediated allergic reactions seems unassailable, studies employing various mice deficient in mast cells or mast cell-associated proteases have yielded divergent conclusions about the roles of mast cells or their proteases in certain other immunological responses. Such "controversial" results call into question the relative utility of various older versus newer approaches to ascertain the roles of mast cells and mast cell proteases in vivo. This review discusses how both older and more recent mouse models have been used to investigate the functions of mast cells and their proteases in health and disease. We particularly focus on settings in which divergent conclusions about the importance of mast cells and their proteases have been supported by studies that employed different models of mast cell or mast cell protease deficiency. We think that two major conclusions can be drawn from such findings: (1) no matter which models of mast cell or mast cell protease deficiency one employs, the conclusions drawn from the experiments always should take into account the potential limitations of the models (particularly abnormalities affecting cell types other than mast cells) and (2) even when analyzing a biological response using a single model of mast cell or mast cell protease deficiency, details of experimental design are critical in efforts to define those conditions under which important contributions of mast cells or their proteases can be identified.
View details for DOI 10.1016/bs.ai.2014.11.002
View details for PubMedID 25727288
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SnapShot: Integrated Type 2 Immune Responses.
Immunity
2015; 43 (2): 408–.e1
View details for PubMedID 26287685
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Editorial overview: Allergy and hypersensitivity: New developments in allergy and type 2 immunity: never a dull moment.
Current opinion in immunology
2015; 36: ix-xi
View details for PubMedID 26337485
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Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice.
Journal of visualized experiments : JoVE
2015: e52753
Abstract
Mast cells (MCs) are hematopoietic cells which reside in various tissues, and are especially abundant at sites exposed to the external environment, such as skin, airways and gastrointestinal tract. Best known for their detrimental role in IgE-dependent allergic reactions, MCs have also emerged as important players in host defense against venom and invading bacteria and parasites. MC phenotype and function can be influenced by microenvironmental factors that may differ according to anatomic location and/or based on the type or stage of development of immune responses. For this reason, we and others have favored in vivo approaches over in vitro methods to gain insight into MC functions. Here, we describe methods for the generation of mouse bone marrow-derived cultured MCs (BMCMCs), their adoptive transfer into genetically MC-deficient mice, and the analysis of the numbers and distribution of adoptively transferred MCs at different anatomical sites. This method, named the 'mast cell knock-in' approach, has been extensively used over the past 30 years to assess the functions of MCs and MC-derived products in vivo. We discuss the advantages and limitations of this method, in light of alternative approaches that have been developed in recent years.
View details for DOI 10.3791/52753
View details for PubMedID 26068439
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Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice.
Journal of visualized experiments : JoVE
2015
Abstract
Mast cells (MCs) are hematopoietic cells which reside in various tissues, and are especially abundant at sites exposed to the external environment, such as skin, airways and gastrointestinal tract. Best known for their detrimental role in IgE-dependent allergic reactions, MCs have also emerged as important players in host defense against venom and invading bacteria and parasites. MC phenotype and function can be influenced by microenvironmental factors that may differ according to anatomic location and/or based on the type or stage of development of immune responses. For this reason, we and others have favored in vivo approaches over in vitro methods to gain insight into MC functions. Here, we describe methods for the generation of mouse bone marrow-derived cultured MCs (BMCMCs), their adoptive transfer into genetically MC-deficient mice, and the analysis of the numbers and distribution of adoptively transferred MCs at different anatomical sites. This method, named the 'mast cell knock-in' approach, has been extensively used over the past 30 years to assess the functions of MCs and MC-derived products in vivo. We discuss the advantages and limitations of this method, in light of alternative approaches that have been developed in recent years.
View details for DOI 10.3791/52753
View details for PubMedID 26068439
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Genomics in the clinic: ethical and policy challenges in clinical next-generation sequencing programs at early adopter USA institutions
PERSONALIZED MEDICINE
2015; 12 (3): 269-282
View details for DOI 10.2217/PME.14.88
View details for Web of Science ID 000355751600011
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beta 7 Integrin Regulates Intra-Marrow Trafficking of Hematopoietic Stem Cells
AMER SOC HEMATOLOGY. 2014
View details for Web of Science ID 000349243508019
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Contribution of Mast Cell-Derived Interleukin-1 beta to Uric Acid Crystal-Induced Acute Arthritis in Mice
ARTHRITIS & RHEUMATOLOGY
2014; 66 (10): 2881-2891
Abstract
Gouty arthritis is caused by the precipitation of monosodium urate monohydrate (MSU) crystals in the joints. While it has been reported that mast cells (MCs) infiltrate gouty tophi, little is known about the actual roles of MCs during acute attacks of gout. This study was undertaken to assess the role of MCs in a mouse model of MSU crystal-induced acute arthritis.We assessed the effects of intraarticular (IA) injection of MSU crystals in various strains of mice with constitutive or inducible MC deficiency or in mice lacking interleukin-1β (IL-1β) or other elements of innate immunity. We also assessed the response to IA injection of MSU crystals in genetically MC-deficient mice after IA engraftment of wild-type or IL-1β(-/-) bone marrow-derived cultured MCs.MCs were found to augment acute tissue swelling following IA injection of MSU crystals in mice. IL-1β production by MCs contributed importantly to MSU crystal-induced tissue swelling, particularly during its early stages. Selective depletion of synovial MCs was able to diminish MSU crystal-induced acute inflammation in the joints.Our findings identify a previously unrecognized role of MCs and MC-derived IL-1β in the early stages of MSU crystal-induced acute arthritis in mice.
View details for DOI 10.1002/art.38747
View details for Web of Science ID 000342744300026
View details for PubMedCentralID PMC4443497
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Contribution of mast cell-derived interleukin-1ß to uric acid crystal-induced acute arthritis in mice.
Arthritis & rheumatology
2014; 66 (10): 2881-2891
Abstract
Gouty arthritis is caused by the precipitation of monosodium urate monohydrate (MSU) crystals in the joints. While it has been reported that mast cells (MCs) infiltrate gouty tophi, little is known about the actual roles of MCs during acute attacks of gout. This study was undertaken to assess the role of MCs in a mouse model of MSU crystal-induced acute arthritis.We assessed the effects of intraarticular (IA) injection of MSU crystals in various strains of mice with constitutive or inducible MC deficiency or in mice lacking interleukin-1β (IL-1β) or other elements of innate immunity. We also assessed the response to IA injection of MSU crystals in genetically MC-deficient mice after IA engraftment of wild-type or IL-1β(-/-) bone marrow-derived cultured MCs.MCs were found to augment acute tissue swelling following IA injection of MSU crystals in mice. IL-1β production by MCs contributed importantly to MSU crystal-induced tissue swelling, particularly during its early stages. Selective depletion of synovial MCs was able to diminish MSU crystal-induced acute inflammation in the joints.Our findings identify a previously unrecognized role of MCs and MC-derived IL-1β in the early stages of MSU crystal-induced acute arthritis in mice.
View details for DOI 10.1002/art.38747
View details for PubMedID 24943488
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Evidence that Meningeal Mast Cells Can Worsen Stroke Pathology in Mice
AMERICAN JOURNAL OF PATHOLOGY
2014; 184 (9): 2493-2504
Abstract
Stroke is the leading cause of adult disability and the fourth most common cause of death in the United States. Inflammation is thought to play an important role in stroke pathology, but the factors that promote inflammation in this setting remain to be fully defined. An understudied but important factor is the role of meningeal-located immune cells in modulating brain pathology. Although different immune cells traffic through meningeal vessels en route to the brain, mature mast cells do not circulate but are resident in the meninges. With the use of genetic and cell transfer approaches in mice, we identified evidence that meningeal mast cells can importantly contribute to the key features of stroke pathology, including infiltration of granulocytes and activated macrophages, brain swelling, and infarct size. We also obtained evidence that two mast cell-derived products, interleukin-6 and, to a lesser extent, chemokine (C-C motif) ligand 7, can contribute to stroke pathology. These findings indicate a novel role for mast cells in the meninges, the membranes that envelop the brain, as potential gatekeepers for modulating brain inflammation and pathology after stroke.
View details for DOI 10.1016/j.ajpath.2014.06.003
View details for PubMedID 25134760
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IgE antibodies and Fc epsilon RI are critical mediators of acquired resistance against honeybee and Russell's viper venom in mice
WILEY-BLACKWELL. 2014: 175
View details for Web of Science ID 000341139400422
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Global Allergy Forum and Second Davos Declaration 2013 Allergy: Barriers to cure - challenges and actions to be taken
ALLERGY
2014; 69 (8): 978-982
View details for DOI 10.1111/all.12406
View details for Web of Science ID 000339436200002
View details for PubMedID 25041525
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Mechanisms of vitamin D-3 metabolite repression of IgE-dependent mast cell activation
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2014; 133 (5): 1356-U590
Abstract
Mast cells have gained notoriety based on their detrimental contributions to IgE-mediated allergic disorders. Although mast cells express the vitamin D receptor (VDR), it is not clear to what extent 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3) or its predominant inactive precursor metabolite in the circulation, 25-hydroxyvitamin D3 (25OHD3), can influence IgE-mediated mast cell activation and passive cutaneous anaphylaxis (PCA) in vivo.We sought to assess whether the vitamin D3 metabolites 25OHD3 and 1α,25(OH)2D3 can repress IgE-dependent mast cell activation through mast cell-25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) and mast cell-VDR activity.We measured the extent of vitamin D3 suppression of IgE-mediated mast cell degranulation and mediator production in vitro, as well as the vitamin D3-induced curtailment of PCA responses in WBB6F1-Kit(W/W-v) or C57BL/6J-Kit(W-sh/W-sh) mice engrafted with mast cells that did or did not express VDR or CYP27B1.Here we show that mouse and human mast cells can convert 25OHD3 to 1α,25(OH)2D3 through CYP27B1 activity and that both of these vitamin D3 metabolites suppressed IgE-induced mast cell-derived proinflammatory and vasodilatory mediator production in a VDR-dependent manner in vitro. Furthermore, epicutaneously applied vitamin D3 metabolites significantly reduced the magnitude of skin swelling associated with IgE-mediated PCA reactions in vivo; a response that required functional mast cell-VDRs and mast cell-CYP27B1.Taken together, our findings provide a mechanistic explanation for the anti-inflammatory effects of vitamin D3 on mast cell function by demonstrating that mast cells can actively metabolize 25OHD3 to dampen IgE-mediated mast cell activation in vitro and in vivo.
View details for DOI 10.1016/j.jaci.2013.11.030
View details for PubMedID 24461581
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A beneficial role for immunoglobulin E in host defense against honeybee venom
WILEY-BLACKWELL. 2014: E2
View details for Web of Science ID 000332335500029
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THE ROLE OF IFN-gamma/MAST CELL AXIS IN THE PATHOGENESIS OF ALLERGIC INFLAMMATION IN ACUTE VERSUS CHRONIC MOUSE MODELS OF ASTHMA
WILEY-BLACKWELL. 2014: 20
View details for Web of Science ID 000332519800032
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Peanut oral immunotherapy results in increased antigen-induced regulatory T-cell function and hypomethylation of forkhead box protein 3 (FOXP3).
journal of allergy and clinical immunology
2014; 133 (2): 500-510
Abstract
The mechanisms contributing to clinical immune tolerance remain incompletely understood. This study provides evidence for specific immune mechanisms that are associated with a model of operationally defined clinical tolerance.Our overall objective was to study laboratory changes associated with clinical immune tolerance in antigen-induced T cells, basophils, and antibodies in subjects undergoing oral immunotherapy (OIT) for peanut allergy.In a phase 1 single-site study, we studied participants (n = 23) undergoing peanut OIT and compared them with age-matched allergic control subjects (n = 20) undergoing standard of care (abstaining from peanut) for 24 months. Participants were operationally defined as clinically immune tolerant (IT) if they had no detectable allergic reactions to a peanut oral food challenge after 3 months of therapy withdrawal (IT, n = 7), whereas those who had an allergic reaction were categorized as nontolerant (NT; n = 13).Antibody and basophil activation measurements did not statistically differentiate between NT versus IT participants. However, T-cell function and demethylation of forkhead box protein 3 (FOXP3) CpG sites in antigen-induced regulatory T cells were significantly different between IT versus NT participants. When IT participants were withdrawn from peanut therapy for an additional 3 months (total of 6 months), only 3 participants remained classified as IT participants, and 4 participants regained sensitivity along with increased methylation of FOXP3 CpG sites in antigen-induced regulatory T cells.In summary, modifications at the DNA level of antigen-induced T-cell subsets might be predictive of a state of operationally defined clinical immune tolerance during peanut OIT.
View details for DOI 10.1016/j.jaci.2013.12.1037
View details for PubMedID 24636474
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Important Role For Mast Cells But Not Basophils In An Adjuvant-Free Model Of Active Anaphylaxis In Mice
MOSBY-ELSEVIER. 2014: AB62
View details for DOI 10.1016/j.jaci.2013.12.245
View details for Web of Science ID 000330241300219
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Type 2 Immunity Can Have a Protective Role In Host Defense Against Venoms In Mice
MOSBY-ELSEVIER. 2014: AB90
View details for DOI 10.1016/j.jaci.2013.12.339
View details for Web of Science ID 000330241300313
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IgE Antibodies and Fc epsilon RI Are Critical For Acquired Resistance Against Honeybee Venom In Mice
MOSBY-ELSEVIER. 2014: AB225
View details for DOI 10.1016/j.jaci.2013.12.803
View details for Web of Science ID 000330241301095
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Peanut oral immunotherapy results in increased antigen-induced regulatory T-cell function and hypomethylation of forkhead box protein 3 (FOXP3).
journal of allergy and clinical immunology
2014; 133 (2): 500-510 e11
View details for DOI 10.1016/j.jaci.2013.12.1037
View details for PubMedID 24636474
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[An allergic response to fight against venoms].
Me´decine sciences : M/S
2014; 30 (2): 127-130
View details for DOI 10.1051/medsci/20143002004
View details for PubMedID 24572105
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A Balanced Look at the Implications of Genomic (and Other "Omics") Testing for Disease Diagnosis and Clinical Care.
Genes
2014; 5 (3): 748-766
Abstract
The tremendous increase in DNA sequencing capacity arising from the commercialization of "next generation" instruments has opened the door to innumerable routes of investigation in basic and translational medical science. It enables very large data sets to be gathered, whose interpretation and conversion into useful knowledge is only beginning. A challenge for modern healthcare systems and academic medical centers is to apply these new methods for the diagnosis of disease and the management of patient care without unnecessary delay, but also with appropriate evaluation of the quality of data and interpretation, as well as the clinical value of the insights gained. Most critically, the standards applied for evaluating these new laboratory data and ensuring that the results and their significance are clearly communicated to patients and their caregivers should be at least as rigorous as those applied to other kinds of medical tests. Here, we present an overview of conceptual and practical issues to be considered in planning for the integration of genomic methods or, in principle, any other type of "omics" testing into clinical care.
View details for DOI 10.3390/genes5030748
View details for PubMedID 25257203
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Rethinking the potential roles of mast cells in skin wound healing and bleomycin-induced skin fibrosis.
The Journal of investigative dermatology
2014; 134 (7): 1802–4
Abstract
Skin wound healing and bleomycin-induced skin fibrosis are thought to reflect complex interactions among diverse cell types. Several lines of evidence have implicated mast cells in these tissue responses. However, data from Willenborg et al. (this issue) and from three other groups suggest that, in at least these examples of cutaneous tissue remodeling, mast cells may not have nonredundant roles.
View details for PubMedID 24924762
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Mast Cells Are Required for Full Expression of Allergen/SEB-Induced Skin Inflammation
JOURNAL OF INVESTIGATIVE DERMATOLOGY
2013; 133 (12): 2695-2705
Abstract
Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease. We recently described an animal model in which repeated epicutaneous applications of a house dust mite extract and Staphylococcal enterotoxin B induced eczematous skin lesions. In this study we showed that global gene expression patterns are very similar between human AD skin and allergen/staphylococcal enterotoxin B-induced mouse skin lesions, particularly in the expression of genes related to epidermal growth/differentiation, skin barrier, lipid/energy metabolism, immune response, or extracellular matrix. In this model, mast cells and T cells, but not B cells or eosinophils, were shown to be required for the full expression of dermatitis, as revealed by reduced skin inflammation and reduced serum IgE levels in mice lacking mast cells or T cells (TCRβ(-/-) or Rag1(-/-)). The clinical severity of dermatitis correlated with the numbers of mast cells, but not eosinophils. Consistent with the idea that T helper type 2 (Th2) cells play a predominant role in allergic diseases, the receptor for the Th2-promoting cytokine thymic stromal lymphopoietin and the high-affinity IgE receptor, FcɛRI, were required to attain maximal clinical scores. Therefore, this clinically relevant model provides mechanistic insights into the pathogenic mechanism of human AD.Journal of Investigative Dermatology advance online publication, 11 July 2013; doi:10.1038/jid.2013.250.
View details for DOI 10.1038/jid.2013.250
View details for Web of Science ID 000327015400010
View details for PubMedID 23752044
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Mast cells suppress murine GVHD in a mechanism independent of CD4+CD25+ regulatory T cells.
Blood
2013; 122 (22): 3659-3665
Abstract
To investigate the role of mast cells in hematopoietic cell transplantation, we assessed graft-versus-host disease (GVHD) in C57BL/6-Kit(W-sh/W-sh) recipients, which virtually lack mast cells, compared with C57BL/6 WT recipients. GVHD was severely exacerbated in C57BL/6-Kit(W-sh/W-sh) mice (median survival time = 13 vs 60 days in wild-type [WT] mice; P < .0001). The increased mortality risk in C57BL/6-Kit(W-sh/W-sh) hosts correlated with increased T-cell numbers in lymph nodes, liver, and gastrointestinal tract sites, as indicated by bioluminescence imaging (P < .001). We did not detect any deficit in the number or function of CD4(+)CD25(+) regulatory T cells (Tregs) in C57BL/6-Kit(W-sh/W-sh) mice. Furthermore, Tregs were equally effective at reducing GVHD in C57BL/6-Kit(W-sh/W-sh) recipients compared with WT recipients containing mast cells. Furthermore, we found that survival of C57BL/6-Kit(W-sh/W-sh) mice during GVHD was significantly improved if the mice were engrafted with bone marrow-derived cultured mast cells from WT C57BL/6 mice but not from interleukin (IL)-10-deficient C57BL/6 mice. These data indicate that the presence of mast cells can significantly reduce GVHD independently of Tregs, by decreasing conventional T-cell proliferation in a mechanism involving IL-10. These experiments support the conclusion that mast cells can mediate a novel immunoregulatory role during hematopoietic cell transplantation.
View details for DOI 10.1182/blood-2013-08-519157
View details for PubMedID 24030387
View details for PubMedCentralID PMC3837515
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A Beneficial Role for Immunoglobulin E in Host Defense against Honeybee Venom.
Immunity
2013; 39 (5): 963-975
Abstract
Allergies are widely considered to be misdirected type 2 immune responses, in which immunoglobulin E (IgE) antibodies are produced against any of a broad range of seemingly harmless antigens. However, components of insect venoms also can sensitize individuals to develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. We found that mice injected with amounts of honeybee venom similar to that which could be delivered in one or two stings developed a specific type 2 immune response that increased their resistance to subsequent challenge with potentially lethal amounts of the venom. Our data indicate that IgE antibodies and the high affinity IgE receptor, FcεRI, were essential for such acquired resistance to honeybee venom. The evidence that IgE-dependent immune responses against venom can enhance survival in mice supports the hypothesis that IgE, which also contributes to allergic disorders, has an important function in protection of the host against noxious substances.
View details for DOI 10.1016/j.immuni.2013.10.005
View details for PubMedID 24210352
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Mast cells: potential positive and negative roles in tumor biology.
Cancer immunology research
2013; 1 (5): 269-279
Abstract
Mast cells are immune cells that reside in virtually all vascularized tissues. Upon activation by diverse mechanisms, mast cells can secrete a broad array of biologically active products that either are stored in the cytoplasmic granules of the cells (e.g., histamine, heparin, various proteases) or are produced de novo upon cell stimulation (e.g., prostaglandins, leukotrienes, cytokines, chemokines, and growth factors). Mast cells are best known for their effector functions during anaphylaxis and acute IgE-associated allergic reactions, but they also have been implicated in a wide variety of processes that maintain health or contribute to disease. There has been particular interest in the possible roles of mast cells in tumor biology. In vitro studies have shown that mast cells have the potential to influence many aspects of tumor biology, including tumor development, tumor-induced angiogenesis, and tissue remodeling, and the shaping of adaptive immune responses to tumors. Yet, the actual contributions of mast cells to tumor biology in vivo remain controversial. Here, we review some basic features of mast cell biology with a special emphasis on those relevant to their potential roles in tumors. We discuss how using in vivo tumor models in combination with models in which mast cell function can be modulated has implicated mast cells in the regulation of host responses to tumors. Finally, we summarize data from studies of human tumors that suggest either beneficial or detrimental roles for mast cells in tumors.
View details for DOI 10.1158/2326-6066.CIR-13-0119
View details for PubMedID 24777963
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Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells.
journal of allergy and clinical immunology
2013; 132 (4): 922-32 e1 16
Abstract
Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood.We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model.C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen.Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces.Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro.
View details for DOI 10.1016/j.jaci.2013.05.004
View details for PubMedID 23810240
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Selective ablation of mast cells or basophils reduces peanut-induced anaphylaxis in mice.
journal of allergy and clinical immunology
2013; 132 (4): 881-8 e1 11
Abstract
Studies with c-kit mutant mast cell (MC)-deficient mice and antibody-mediated depletion of basophils suggest that both MCs and basophils can contribute to peanut-induced anaphylaxis (PIA). However, interpretation of data obtained by using such approaches is complicated because c-kit mutant mice have several phenotypic abnormalities in addition to MC deficiency and because basophil-depleting antibodies can also react with MCs.We analyzed (1) the changes in the features of PIA in mice after the selective and inducible ablation of MCs or basophils and (2) the possible importance of effector cells other than MCs and basophils in the PIA response.Wild-type and various mutant mice were orally sensitized with peanut extract and cholera toxin weekly for 4 weeks and challenged intraperitoneally with peanut extract 2 weeks later.Peanut-challenged, MC-deficient Kit(W-sh/W-sh) mice had reduced immediate hypothermia, as well as a late-phase decrease in body temperature that was abrogated by antibody-mediated depletion of neutrophils. Diphtheria toxin-mediated selective depletion of MCs or basophils in Mcpt5-Cre;iDTR and Mcpt8(DTR) mice, respectively, and treatment of wild-type mice with the basophil-depleting antibody Ba103 significantly reduced peanut-induced hypothermia. Non-c-kit mutant MC- and basophil-deficient Cpa3-Cre;Mcl-1(fl/fl) mice had reduced but still significant responses to peanut.Inducible and selective ablation of MCs or basophils in non-c-kit mutant mice can significantly reduce PIA, but partial responses to peanut can still be observed in the virtual absence of both cell types. The neutrophilia in Kit(W-sh/W-sh) mice might influence the responses of these mice in this PIA model.
View details for DOI 10.1016/j.jaci.2013.06.008
View details for PubMedID 23915716
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Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells.
journal of allergy and clinical immunology
2013; 132 (4): 922-932 e16
Abstract
Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood.We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model.C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen.Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces.Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro.
View details for DOI 10.1016/j.jaci.2013.05.004
View details for PubMedID 23810240
-
Selective ablation of mast cells or basophils reduces peanut-induced anaphylaxis in mice.
journal of allergy and clinical immunology
2013; 132 (4): 881-888 e11
Abstract
Studies with c-kit mutant mast cell (MC)-deficient mice and antibody-mediated depletion of basophils suggest that both MCs and basophils can contribute to peanut-induced anaphylaxis (PIA). However, interpretation of data obtained by using such approaches is complicated because c-kit mutant mice have several phenotypic abnormalities in addition to MC deficiency and because basophil-depleting antibodies can also react with MCs.We analyzed (1) the changes in the features of PIA in mice after the selective and inducible ablation of MCs or basophils and (2) the possible importance of effector cells other than MCs and basophils in the PIA response.Wild-type and various mutant mice were orally sensitized with peanut extract and cholera toxin weekly for 4 weeks and challenged intraperitoneally with peanut extract 2 weeks later.Peanut-challenged, MC-deficient Kit(W-sh/W-sh) mice had reduced immediate hypothermia, as well as a late-phase decrease in body temperature that was abrogated by antibody-mediated depletion of neutrophils. Diphtheria toxin-mediated selective depletion of MCs or basophils in Mcpt5-Cre;iDTR and Mcpt8(DTR) mice, respectively, and treatment of wild-type mice with the basophil-depleting antibody Ba103 significantly reduced peanut-induced hypothermia. Non-c-kit mutant MC- and basophil-deficient Cpa3-Cre;Mcl-1(fl/fl) mice had reduced but still significant responses to peanut.Inducible and selective ablation of MCs or basophils in non-c-kit mutant mice can significantly reduce PIA, but partial responses to peanut can still be observed in the virtual absence of both cell types. The neutrophilia in Kit(W-sh/W-sh) mice might influence the responses of these mice in this PIA model.
View details for DOI 10.1016/j.jaci.2013.06.008
View details for PubMedID 23915716
View details for PubMedCentralID PMC3794715
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PLA2G3 promotes mast cell maturation and function.
Nature immunology
2013; 14 (6): 527-529
View details for DOI 10.1038/ni.2612
View details for PubMedID 23685814
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Genetic analysis of the role of mast cell- and basophil-derived TNF in severe sepsis
AMER ASSOC IMMUNOLOGISTS. 2013
View details for Web of Science ID 000322987105022
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Integration of Genomic Medicine into Pathology Residency Training The Stanford Open Curriculum
JOURNAL OF MOLECULAR DIAGNOSTICS
2013; 15 (2): 141-148
Abstract
Next-generation sequencing methods provide an opportunity for molecular pathology laboratories to perform genomic testing that is far more comprehensive than single-gene analyses. Genome-based test results are expected to develop into an integral component of diagnostic clinical medicine and to provide the basis for individually tailored health care. To achieve these goals, rigorous interpretation of high-quality data must be informed by the medical history and the phenotype of the patient. The discipline of pathology is well positioned to implement genome-based testing and to interpret its results, but new knowledge and skills must be included in the training of pathologists to develop expertise in this area. Pathology residents should be trained in emerging technologies to integrate genomic test results appropriately with more traditional testing, to accelerate clinical studies using genomic data, and to help develop appropriate standards of data quality and evidence-based interpretation of these test results. We have created a genomic pathology curriculum as a first step in helping pathology residents build a foundation for the understanding of genomic medicine and its implications for clinical practice. This curriculum is freely accessible online.
View details for DOI 10.1016/j.jmoldx.2012.11.003
View details for Web of Science ID 000315841600001
View details for PubMedID 23313248
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Mast cell anaphylatoxin receptor expression can enhance IgE-dependent skin inflammation in mice
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2013; 131 (2): 541-?
Abstract
Mast cells express receptors for complement anaphylatoxins C3a and C5a (ie, C3a receptor [C3aR] and C5a receptor [C5aR]), and C3a and C5a are generated during various IgE-dependent immediate hypersensitivity reactions in vivo. However, it is not clear to what extent mast cell expression of C3aR or C5aR influences C3a- or C5a-induced cutaneous responses or IgE-dependent mast cell activation and passive cutaneous anaphylaxis (PCA) in vivo.We sought to assess whether mouse skin mast cell expression of C3aR or C5aR influences (1) the cells' responsiveness to intradermal injections of C3a or C5a or (2) the extent of IgE-dependent mast cell degranulation and PCA in vivo.We measured the magnitude of cutaneous responses to intradermal injections of C3a or C5a and the extent of IgE-dependent mast cell degranulation and PCA responses in mice containing mast cells that did or did not express C3aR or C5aR.The majority of the skin swelling induced by means of intradermal injection of C3a or C5a required that mast cells at the site expressed C3aR or C5aR, respectively, and the extent of IgE-dependent degranulation of skin mast cells and IgE-dependent PCA was significantly reduced when mast cells lacked either C3aR or C5aR. IgE-dependent PCA responses associated with local increases in C3a levels occurred in antibody-deficient mice but not in mice deficient in FcɛRIγ.Expression of C3aR and C5aR by skin mast cells contributes importantly to the ability of C3a and C5a to induce skin swelling and can enhance mast cell degranulation and inflammation during IgE-dependent PCA in vivo.
View details for DOI 10.1016/j.jaci.2012.05.009
View details for Web of Science ID 000314661500034
View details for PubMedID 22728083
View details for PubMedCentralID PMC3597773
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Meningeal Mast Cells Can Exacerbate Stroke Pathology In Mice
LIPPINCOTT WILLIAMS & WILKINS. 2013
View details for Web of Science ID 000330540200433
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Evidence that mast cells are not required for healing of splinted cutaneous excisional wounds in mice.
PloS one
2013; 8 (3)
Abstract
Wound healing is a complex biological process involving the interaction of many cell types to replace lost or damaged tissue. Although the biology of wound healing has been extensively investigated, few studies have focused on the role of mast cells. In this study, we investigated the possible role of mast cells in wound healing by analyzing aspects of cutaneous excisional wound healing in three types of genetically mast cell-deficient mice. We found that C57BL/6-Kit(W-sh/W-sh), WBB6F1-Kit(W/W-v), and Cpa3-Cre; Mcl-1(fl/fl) mice re-epithelialized splinted excisional skin wounds at rates very similar to those in the corresponding wild type or control mice. Furthermore, at the time of closure, scars were similar in the genetically mast cell-deficient mice and the corresponding wild type or control mice in both quantity of collagen deposition and maturity of collagen fibers, as evaluated by Masson's Trichrome and Picro-Sirius red staining. These data indicate that mast cells do not play a significant non-redundant role in these features of the healing of splinted full thickness excisional cutaneous wounds in mice.
View details for DOI 10.1371/journal.pone.0059167
View details for PubMedID 23544053
View details for PubMedCentralID PMC3609818
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New models for analyzing mast cell functions in vivo
TRENDS IN IMMUNOLOGY
2012; 33 (12): 613-625
Abstract
In addition to their well-accepted role as critical effector cells in anaphylaxis and other acute IgE-mediated allergic reactions, mast cells (MCs) have been implicated in a wide variety of processes that contribute to disease or help to maintain health. Although some of these roles were first suggested by analyses of MC products or functions in vitro, it is critical to determine whether, and under which circumstances, such potential roles actually can be performed by MCs in vivo. This review discusses recent advances in the development and analysis of mouse models to investigate the roles of MCs and MC-associated products during biological responses in vivo, and comments on some of the similarities and differences in the results obtained with these newer versus older models of MC deficiency.
View details for DOI 10.1016/j.it.2012.09.008
View details for Web of Science ID 000312055700005
View details for PubMedID 23127755
View details for PubMedCentralID PMC3572764
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Evidence questioning cromolyn's effectiveness and selectivity as a 'mast cell stabilizer' in mice
LABORATORY INVESTIGATION
2012; 92 (10): 1472-1482
Abstract
Cromolyn, widely characterized as a 'mast cell stabilizer', has been used in mice to investigate the biological roles of mast cells in vivo. However, it is not clear to what extent cromolyn can either limit the function of mouse mast cells or influence biological processes in mice independently of effects on mast cells. We confirmed that cromolyn (at 10 mg/kg in vivo or 10-100 μM in vitro) can inhibit IgE-dependent mast cell activation in rats in vivo (measuring Evans blue extravasation in passive cutaneous anaphylaxis (PCA) and increases in plasma histamine in passive systemic anaphylaxis (PSA)) and in vitro (measuring peritoneal mast cell (PMC) β-hexosaminidase release and prostaglandin D(2) synthesis). However, under the conditions tested, cromolyn did not inhibit those mast cell-dependent responses in mice. In mice, cromolyn also failed to inhibit the ear swelling or leukocyte infiltration at sites of PCA. Nor did cromolyn inhibit IgE-independent degranulation of mouse PMCs induced by various stimulators in vitro. At 100 mg/kg, a concentration 10 times higher than that which inhibited PSA in rats, cromolyn significantly inhibited the increases in plasma concentrations of mouse mast cell protease-1 (but not of histamine) during PSA, but had no effect on the reduction in body temperature in this setting. Moreover, this concentration of cromolyn (100 mg/kg) also inhibited LPS-induced TNF production in genetically mast cell-deficient C57BL/6-Kit(W-sh/W-sh) mice in vivo. These results question cromolyn's effectiveness and selectivity as an inhibitor of mast cell activation and mediator release in the mouse.
View details for DOI 10.1038/labinvest.2012.116
View details for Web of Science ID 000309324600009
View details for PubMedID 22906983
View details for PubMedCentralID PMC3580174
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The Chymase Mouse Mast Cell Protease 4 Degrades TNF, Limits Inflammation, and Promotes Survival in a Model of Sepsis
AMERICAN JOURNAL OF PATHOLOGY
2012; 181 (3): 875-886
Abstract
Mouse mast cell protease 4 (mMCP-4), the mouse counterpart of human mast cell chymase, is thought to have proinflammatory effects in innate or adaptive immune responses associated with mast cell activation. However, human chymase can degrade the proinflammatory cytokine TNF, a mediator that can be produced by mast cells and many other cell types. We found that mMCP-4 can reduce levels of mouse mast cell-derived TNF in vitro through degradation of transmembrane and soluble TNF. We assessed the effects of interactions between mMCP-4 and TNF in vivo by analyzing the features of a classic model of polymicrobial sepsis, cecal ligation and puncture (CLP), in C57BL/6J-mMCP-4-deficient mice versus C57BL/6J wild-type mice, and in C57BL/6J-Kit(W-sh/W-sh) mice containing adoptively transferred mast cells that were either wild type or lacked mMCP-4, TNF, or both mediators. The mMCP-4-deficient mice exhibited increased levels of intraperitoneal TNF, higher numbers of peritoneal neutrophils, and increased acute kidney injury after CLP, and also had significantly higher mortality after this procedure. Our findings support the conclusion that mMCP-4 can enhance survival after CLP at least in part by limiting detrimental effects of TNF, and suggest that mast cell chymase may represent an important negative regulator of TNF in vivo.
View details for DOI 10.1016/j.ajpath.2012.05.013
View details for Web of Science ID 000309251100016
View details for PubMedID 22901752
View details for PubMedCentralID PMC3432424
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Critical role of P1-Runx1 in mouse basophil development
BLOOD
2012; 120 (1): 76-85
Abstract
Runx1(P1N/P1N) mice are deficient in the transcription factor distal promoter-derived Runt-related transcription factor 1 (P1-Runx1) and have a > 90% reduction in the numbers of basophils in the BM, spleen, and blood. In contrast, Runx1(P1N/P1N) mice have normal numbers of the other granulocytes (neutrophils and eosinophils). Although basophils and mast cells share some common features, Runx1(P1N/P1N) mice have normal numbers of mast cells in multiple tissues. Runx1(P1N/P1N) mice fail to develop a basophil-dependent reaction, IgE-mediated chronic allergic inflammation of the skin, but respond normally when tested for IgE- and mast cell-dependent passive cutaneous anaphylaxis in vivo or IgE-dependent mast cell degranulation in vitro. These results demonstrate that Runx1(P1N/P1N) mice exhibit markedly impaired function of basophils, but not mast cells. Infection with the parasite Strongyloides venezuelensis and injections of IL-3, each of which induces marked basophilia in wild-type mice, also induce modest expansions of the very small populations of basophils in Runx1(P1N/P1N) mice. Finally, Runx1(P1N/P1N) mice have normal numbers of the granulocyte progenitor cells, SN-Flk2(+/-), which can give rise to all granulocytes, but exhibit a > 95% reduction in basophil progenitors. The results of the present study suggest that P1-Runx1 is critical for a stage of basophil development between SN-Flk2(+/-) cells and basophil progenitors.
View details for DOI 10.1182/blood-2011-12-399113
View details for Web of Science ID 000307411100015
View details for PubMedID 22611151
View details for PubMedCentralID PMC3390962
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Modulation of mTOR Effector Phosphoproteins in Blood Basophils from Allergic Patients
JOURNAL OF CLINICAL IMMUNOLOGY
2012; 32 (3): 565-573
Abstract
The mammalian target of rapamycin (mTOR) pathway contributes to various immunoinflammatory processes. Yet, its potential involvement in basophil responses in allergy remains unclear. In this pilot study, we quantified two key mTOR effector phosphoproteins, the eukaryotic initiation factor 4E (peIF4E) and S6 ribosomal protein (pS6rp), in blood basophils from nut allergy patients (NA, N = 16) and healthy controls (HC, N = 13). Without stimulation in vitro, basophil peIF4E levels were higher in NA than HC subjects (P = 0.014). Stimulation with nut (offending) but not chicken / rice (non-offending) extract increased basophil peIF4E and pS6rp levels (+32%, P = 0.018, and +98%, P = 0.0026, respectively) in NA but not HC subjects, concomitant with increased surface levels of CD203c and CD63, both known to reflect basophil activation. Pre-treatment with the mTOR inhibitor rapamycin decreased pS6rp and CD203c responses in nut extract-stimulated basophils in NA subjects. Thus, basophil responses to offending allergens are associated with modulation of mTOR effector phosphoproteins.
View details for DOI 10.1007/s10875-012-9651-x
View details for Web of Science ID 000305982100019
View details for PubMedID 22350221
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IgE and mast cells in allergic disease
NATURE MEDICINE
2012; 18 (5): 693-704
Abstract
Immunoglobulin E (IgE) antibodies and mast cells have been so convincingly linked to the pathophysiology of anaphylaxis and other acute allergic reactions that it can be difficult to think of them in other contexts. However, a large body of evidence now suggests that both IgE and mast cells are also key drivers of the long-term pathophysiological changes and tissue remodeling associated with chronic allergic inflammation in asthma and other settings. Such potential roles include IgE-dependent regulation of mast-cell functions, actions of IgE that are largely independent of mast cells and roles of mast cells that do not directly involve IgE. In this review, we discuss findings supporting the conclusion that IgE and mast cells can have both interdependent and independent roles in the complex immune responses that manifest clinically as asthma and other allergic disorders.
View details for DOI 10.1038/nm.2755
View details for Web of Science ID 000303763500037
View details for PubMedID 22561833
View details for PubMedCentralID PMC3597223
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Davos declaration: allergy as a global problem (vol 67, pg 141, 2012)
ALLERGY
2012; 67 (5): 712
View details for DOI 10.1111/j.1398-9995.2012.02814.x
View details for Web of Science ID 000302613500019
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Enhancement of IgE- and mast cell-dependent cutaneous inflammation by mast cell expression of C3aR and C5aR
99th Annual Meeting of the American-Association-of-Immunologists
AMER ASSOC IMMUNOLOGISTS. 2012
View details for Web of Science ID 000304659702255
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Between hype and hope: whole-genome sequencing in clinical medicine.
Personalized medicine
2012; 9 (3): 243–46
View details for PubMedID 29758791
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Reduced mast cell and basophil numbers and function in Cpa3-Cre; Mcl-1(fl/fl) mice
BLOOD
2011; 118 (26): 6930-6938
Abstract
It has been reported that the intracellular antiapoptotic factor myeloid cell leukemia sequence 1 (Mcl-1) is required for mast cell survival in vitro, and that genetic manipulation of Mcl-1 can be used to delete individual hematopoietic cell populations in vivo. In the present study, we report the generation of C57BL/6 mice in which Cre recombinase is expressed under the control of a segment of the carboxypeptidase A3 (Cpa3) promoter. C57BL/6-Cpa3-Cre; Mcl-1(fl/fl) mice are severely deficient in mast cells (92%-100% reduced in various tissues analyzed) and also have a marked deficiency in basophils (58%-78% reduced in the compartments analyzed), whereas the numbers of other hematopoietic cell populations exhibit little or no changes. Moreover, Cpa3-Cre; Mcl-1(fl/fl) mice exhibited marked reductions in the tissue swelling and leukocyte infiltration that are associated with both mast cell- and IgE-dependent passive cutaneous anaphylaxis (except at sites engrafted with in vitro-derived mast cells) and a basophil- and IgE-dependent model of chronic allergic inflammation, and do not develop IgE-dependent passive systemic anaphylaxis. Our findings support the conclusion that Mcl-1 is required for normal mast cell and basophil development/survival in vivo in mice, and also suggest that Cpa3-Cre; Mcl-1(fl/fl) mice may be useful in analyzing the roles of mast cells and basophils in health and disease.
View details for DOI 10.1182/blood-2011-03-343962
View details for Web of Science ID 000298401000030
View details for PubMedID 22001390
View details for PubMedCentralID PMC3245213
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Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils
NATURE IMMUNOLOGY
2011; 12 (11): 1035-1044
Abstract
Hematopoietic cells, including lymphoid and myeloid cells, can develop into phenotypically distinct 'subpopulations' with different functions. However, evidence indicates that some of these subpopulations can manifest substantial plasticity (that is, undergo changes in their phenotype and function). Here we focus on the occurrence of phenotypically distinct subpopulations in three lineages of myeloid cells with important roles in innate and acquired immunity: macrophages, mast cells and neutrophils. Cytokine signals, epigenetic modifications and other microenvironmental factors can substantially and, in some cases, rapidly and reversibly alter the phenotype of these cells and influence their function. This suggests that regulation of the phenotype and function of differentiated hematopoietic cells by microenvironmental factors, including those generated during immune responses, represents a common mechanism for modulating innate or adaptive immunity.
View details for DOI 10.1038/ni.2109
View details for Web of Science ID 000296500100008
View details for PubMedID 22012443
View details for PubMedCentralID PMC3412172
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Mast cell chymase reduces the toxicity of Gila monster venom, scorpion venom, and vasoactive intestinal polypeptide in mice
JOURNAL OF CLINICAL INVESTIGATION
2011; 121 (10): 4180-4191
Abstract
Mast cell degranulation is important in the pathogenesis of anaphylaxis and allergic disorders. Many animal venoms contain components that can induce mast cell degranulation, and this has been thought to contribute to the pathology and mortality caused by envenomation. However, we recently reported evidence that mast cells can enhance the resistance of mice to the venoms of certain snakes and that mouse mast cell-derived carboxypeptidase A3 (CPA3) can contribute to this effect. Here, we investigated whether mast cells can enhance resistance to the venom of the Gila monster, a toxic component of that venom (helodermin), and the structurally similar mammalian peptide, vasoactive intestinal polypeptide (VIP). Using 2 types of mast cell-deficient mice, as well as mice selectively lacking CPA3 activity or the chymase mouse mast cell protease-4 (MCPT4), we found that mast cells and MCPT4, which can degrade helodermin, can enhance host resistance to the toxicity of Gila monster venom. Mast cells and MCPT4 also can limit the toxicity associated with high concentrations of VIP and can reduce the morbidity and mortality induced by venoms from 2 species of scorpions. Our findings support the notion that mast cells can enhance innate defense by degradation of diverse animal toxins and that release of MCPT4, in addition to CPA3, can contribute to this mast cell function.
View details for DOI 10.1172/JCI46139
View details for Web of Science ID 000295601000043
View details for PubMedID 21926462
View details for PubMedCentralID PMC3195461
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Identification of an IFN-gamma/mast cell axis in a mouse model of chronic asthma
JOURNAL OF CLINICAL INVESTIGATION
2011; 121 (8): 3133-3143
Abstract
Asthma is considered a Th2 cell–associated disorder. Despite this, both the Th1 cell–associated cytokine IFN-γ and airway neutrophilia have been implicated in severe asthma. To investigate the relative contributions of different immune system components to the pathogenesis of asthma, we previously developed a model that exhibits several features of severe asthma in humans, including airway neutrophilia and increased lung IFN-γ. In the present studies, we tested the hypothesis that IFN-γ regulates mast cell function in our model of chronic asthma. Engraftment of mast cell–deficient KitW(-sh/W-sh) mice, which develop markedly attenuated features of disease, with wild-type mast cells restored disease pathology in this model of chronic asthma. However, disease pathology was not fully restored by engraftment with either IFN-γ receptor 1–null (Ifngr1–/–) or Fcε receptor 1γ–null (Fcer1g–/–) mast cells. Additional analysis, including gene array studies, showed that mast cell expression of IFN-γR contributed to the development of many FcεRIγ-dependent and some FcεRIγ-independent features of disease in our model, including airway hyperresponsiveness, neutrophilic and eosinophilic inflammation, airway remodeling, and lung expression of several cytokines, chemokines, and markers of an alternatively activated macrophage response. These findings identify a previously unsuspected IFN-γ/mast cell axis in the pathology of chronic allergic inflammation of the airways in mice.
View details for DOI 10.1172/JCI43598
View details for Web of Science ID 000293495500024
View details for PubMedID 21737883
View details for PubMedCentralID PMC3148724
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Evidence that the endothelin A receptor can enhance IgE-dependent anaphylaxis in mice
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2011; 128 (2): 424-426
View details for DOI 10.1016/j.jaci.2011.04.012
View details for Web of Science ID 000293280800030
View details for PubMedCentralID PMC3565840
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The chymase, mouse mast cell protease 4, degrades TNF, limits inflammation, and promotes survival in a mouse model of sepsis
AMER ASSOC IMMUNOLOGISTS. 2011
View details for Web of Science ID 000209751706056
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Increased activities of cysteine cathepsins in mouse models of asthma
AMER ASSOC IMMUNOLOGISTS. 2011
View details for Web of Science ID 000209751706050
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MAST CELLS SUPPRESS GVHD IN A MECHANISM INDEPENDENT OF CD4(+)CD25(+) REGULATORY T CELLS
ELSEVIER SCIENCE INC. 2011: S328
View details for DOI 10.1016/j.bbmt.2010.12.524
View details for Web of Science ID 000287350500487
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Basophil CD203c Levels Are Increased at Baseline and Can Be Used to Monitor Omalizumab Treatment in Subjects with Nut Allergy
INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY
2011; 154 (4): 318-327
Abstract
Basophils contribute to anaphylaxis and allergies. We examined the utility of assessing basophil-associated surface antigens (CD11b/CD63/CD123/CD203c/CD294) in characterizing and monitoring subjects with nut allergy.We used flow cytometry to analyze basophils at baseline (without any activation) and after ex vivo stimulation of whole blood by addition of nut or other allergens for 2, 10, and 30 min. We also evaluated whether basophil expression of CD11b/CD63/CD123/CD203c/CD294 was altered in subjects treated with anti-IgE monoclonal antibody (omalizumab) to reduce plasma levels of IgE.We demonstrate that basophil CD203c levels are increased at baseline in subjects with nut allergy compared to healthy controls (13 subjects in each group, p < 0.0001). Furthermore, we confirm that significantly increased expression of CD203c occurs on subject basophils when stimulated with the allergen to which the subject is sensitive and can be detected rapidly (10 min of stimulation, n = 11, p < 0.0008). In 5 subjects with severe peanut allergy, basophil CD203c expression following stimulation with peanut allergen was significantly decreased (p < 0.05) after 4 and 8 weeks of omalizumab treatment but returned toward pretreatment levels after treatment cessation.Subjects with nut allergy show an increase of basophil CD203c levels at baseline and following rapid ex vivo stimulation with nut allergen. Both can be reduced by omalizumab therapy. These results highlight the potential of using basophil CD203c levels for baseline diagnosis and therapeutic monitoring in subjects with nut allergy.
View details for DOI 10.1159/000321824
View details for Web of Science ID 000288529200007
View details for PubMedID 20975283
View details for PubMedCentralID PMC3214954
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Mast Cells: Effector Cells of Anaphylaxis
ANAPHYLAXIS AND HYPERSENSITIVITY REACTIONS
2011: 47–68
View details for DOI 10.1007/978-1-60327-951-2_4
View details for Web of Science ID 000286149900004
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Mast cells
INFLAMMATION AND ALLERGY DRUG DESIGN
2011: 79–105
View details for Web of Science ID 000337021900008
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MAST CELLS AND IMMUNOREGULATION/IMMUNOMODULATION
MAST CELL BIOLOGY: CONTEMPORARY AND EMERGING TOPICS
2011; 716: 186-211
Abstract
Mast cells often represent one of the first cells of the immune system to interact with environmental antigens, invading pathogens or environmentally-derived toxins. Mast cells also can undergo alterations in phenotype, anatomic distribution and numbers during innate or adaptive immune responses. In addition to their well-known roles as effector cells during IgE- and antigen-induced allergic reactions, mast cells can be activated by many other signals, including some that are derived directly from pathogens or which are generated during innate or adaptive immune responses. Mast cells also express many costimulatory molecules with immunoregulatory activities and can secrete many products that can positively or negatively regulate immune responses. In this chapter, we describe mouse models used for analyzing mast-cell function in vivo and illustrate how such models have been used to identify positive or negative immunomodulatory roles for mast cells during specific innate or adaptive immune responses. We also briefly describe some of the mast-cell functions, products and surface receptors that have the potential to permit mast cells to promote or suppress immune responses that can either enhance host defense or contribute to disease.
View details for Web of Science ID 000290066600011
View details for PubMedID 21713658
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Antiinflammatory and immunosuppressive functions of mast cells.
Methods in molecular biology (Clifton, N.J.)
2011; 677: 207-220
Abstract
Through the release of biologically active products, mast cells function as important effector and immunoregulatory cells in diverse immunological reactions and other biological responses; for example, mast cells promote inflammation and other tissue changes in immunoglobulin E (IgE)-associated allergic disorders, as well as in certain innate and adaptive immune responses that are thought to be independent of IgE. Despite the mast cell's well-deserved reputation as a promoter of inflammation, others and we have used bone marrow-derived cultured mast cell (BMCMC) engrafted mast cell-deficient c-kit-mutant mice (so-called "mast cell knock-in" mice) to show that mast cells can also have important antiinflammatory and immunosuppressive functions in vivo. An early study showed that mast cells can contribute to susceptibility to ultraviolet B (UVB)-induced immunosuppression in one model of contact hypersensitivity (CHS), through effects mediated at least in part by histamine. Subsequently, it was reported that mast cells can mediate negative immunomodulatory effects following Anopheles mosquito bites, and in peripheral tolerance to skin allografts; however, the mechanism(s) by which mast cells mediate immunosuppressive functions in these two studies remains to be elucidated. Finally, we showed that mast cells and mast cell-derived IL-10 can limit the magnitude of and promote the resolution of certain CHS responses, and suppress the inflammation and skin injury associated with innate cutaneous responses to chronic low-dose UVB irradiation. This chapter outlines the generation of BMCMCs, a powerful model system commonly used to: (1) identify potential mast cell mediators in vitro; (2) study the mechanisms of mast cell activation and mediator release in response to specific stimuli in vitro; and (3) engraft mast cell-deficient mice to study the effector and immunoregulatory roles of mast cells or specific mast cell mediators in diverse immunological responses in vivo.
View details for DOI 10.1007/978-1-60761-869-0_15
View details for PubMedID 20941613
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Mast Cells Reduce Gvhd Severity In Allogeneic Transplantation by Reducing the Proliferation of Conventional T Cells
AMER SOC HEMATOLOGY. 2010: 112
View details for Web of Science ID 000289662200244
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Thymic Stromal Lymphopoietin Contributes to Myeloid Hyperplasia and Increased Immunoglobulins, But Not Epidermal Hyperplasia, in RabGEF1-Deficient Mice
AMERICAN JOURNAL OF PATHOLOGY
2010; 177 (5): 2411-2420
Abstract
Mice overexpressing the proallergic cytokine thymic stromal lymphopoietin (TSLP) in the skin develop a pathology resembling atopic dermatitis. RabGEF1, a guanine nucleotide exchange factor for Rab5 GTPase, is a negative regulator of IgE-dependent mast cell activation, and Rabgef1-/- and TSLP transgenic mice share many similar phenotypic characteristics, including elevated serum IgE levels and severe skin inflammation, with infiltrates of both lymphocytes and eosinophils. We report here that Rabgef1-/- mice also develop splenomegaly, lymphadenopathy, myeloid hyperplasia, and high levels of TSLP. Rabgef1-/-TSLPR-/- mice, which lack TSLP/TSLP receptor (TSLPR) signaling, had levels of blood neutrophils, spleen myeloid cells, and serum IL-4, IgG1, and IgE levels that were significantly reduced compared with those in Rabgef1-/-TSLPR+/+ mice. However, Rabgef1-/-TSLPR-/- mice, like Rag1- or eosinophil-deficient Rabgef1-/- mice, developed cutaneous inflammation and epidermal hyperplasia. Therefore, in Rabgef1-/- mice, TSLP/TSLPR interactions are not required for the development of epidermal hyperplasia but contribute to the striking myeloid hyperplasia and overproduction of immunoglobulins observed in these animals. Our study shows that RabGEF1 can negatively regulate TSLP production in vivo and that excessive production of TSLP contributes to many of the phenotypic abnormalities in Rabgef1-/- mice. However, the marked epidermal hyperplasia, cutaneous inflammation, and increased numbers of dermal mast cells associated with RabGEF1 deficiency can develop via a TSLPR-independent pathway, as well as in the absence of Rag1 or eosinophils.
View details for DOI 10.2353/ajpath.2010.100181
View details for Web of Science ID 000284182900028
View details for PubMedID 20829437
View details for PubMedCentralID PMC2966799
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Mast cells in allergy and infection: Versatile effector and regulatory cells in innate and adaptive immunity
EUROPEAN JOURNAL OF IMMUNOLOGY
2010; 40 (7): 1843-1851
Abstract
Mast cells are widely distributed in tissues, particularly near surfaces exposed to the environment. Mast cells can be activated to secrete diverse mediators and cytokines by IgE and specific Ag and many other stimuli, including products derived from either pathogens or the host during innate immune responses. Although mast cells are best known for their role in IgE-associated allergic disorders, mast cells can also exacerbate models of autoimmunity, enhance the sensitization and/or effector phases of certain cutaneous contact hypersensitivity responses, and increase inflammation and mortality during some severe bacterial infections. In other settings, however, mast cells can limit inflammation and tissue injury: mast cells promote host resistance in certain models of bacterial or parasite infection, limit pathology during some acquired immune responses to environmental Ag, including examples of severe contact hypersensitivity, and have adjuvant-like properties that can enhance the development of protective immunity against pathogens. These and other findings suggest that mast cells occupy a critical niche at the interface of innate and acquired immunity, where, depending on circumstances that remain to be fully understood, mast cells may function to perturb or help to restore homeostasis (or both), with consequences that can either promote health or contribute to disease.
View details for DOI 10.1002/eji.201040559
View details for Web of Science ID 000280220600012
View details for PubMedID 20583030
View details for PubMedCentralID PMC3581154
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Regulation of secretory granule size by the precise generation and fusion of unit granules
JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
2010; 14 (7): 1904-1916
Abstract
Morphometric evidence derived from studies of mast cells, pancreatic acinar cells and other cell types supports a model in which the post-Golgi processes that generate mature secretory granules can be resolved into three steps: (1) fusion of small, Golgi-derived progranules to produce immature secretory granules which have a highly constrained volume; (2) transformation of such immature granules into mature secretory granules, a process often associated with a reduction in the maturing granule's volume, as well as changes in the appearance of its content and (3) fusion of secretory granules of the smallest size, termed 'unit granules', forming granules whose volumes are multiples of the unit granule's volume. Mutations which perturb this process can cause significant pathology. For example, Chediak-Higashi syndrome / lysosomal trafficking regulator (CHS)/(Lyst) mutations result in giant secretory granules in a number of cell types in human beings with the Chediak-Higashi syndrome and in 'beige' (Lyst(bg)/Lyst(bg)) mice. Analysis of the secretory granules of mast cells and pancreatic acinar cells in Lyst-deficient beige mice suggests that beige mouse secretory granules retain the ability to fuse randomly with other secretory granules no matter what the size of the fusion partners. By contrast, in normal mice, the pattern of granule-granule fusion occurs exclusively by the addition of unit granules, either to each other or to larger granules. The normal pattern of fusion is termed unit addition and the fusion evident in cells with CHS/Lyst mutations is called random addition. The proposed model of secretory granule formation has several implications. For example, in neurosecretory cells, the secretion of small amounts of cargo in granules constrained to a very narrow size increases the precision of the information conveyed by secretion. By contrast, in pancreatic acinar cells and mast cells, large granules composed of multiple unit granules permit the cells to store large amounts of material without requiring the amount of membrane necessary to package the same amount of cargo into small granules. In addition, the formation of mature secretory granules that are multimers of unit granules provides a mechanism for mixing in large granules the contents of unit granules which differ in their content of cargo.
View details for DOI 10.1111/j.1582-4934.2010.01071.x
View details for Web of Science ID 000281141900003
View details for PubMedID 20406331
View details for PubMedCentralID PMC2909340
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Basophil CD203c levels are increased at baseline and can be used to monitor omalizumab treatment in subjects with nut allergy
WILEY-BLACKWELL. 2010: 503
View details for Web of Science ID 000329462102364
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Distinguishing Mast Cell and Granulocyte Differentiation at the Single-Cell Level
CELL STEM CELL
2010; 6 (4): 361-368
Abstract
The lineage restriction of prospectively isolated hematopoietic progenitors has been traditionally assessed by bulk in vitro culture and transplantation of large number of cells in vivo. These methods, however, cannot distinguish between homogenous multipotent or heterogeneous lineage-restricted populations. Using clonal assays of 1 or 5 cells in vitro, single-cell quantitative gene expression analyses, and transplantation of mice with low numbers of cells, we show that a common myeloid progenitor (CMP) is Sca-1(lo)lin(-)c-Kit(+)CD27(+)Flk-2(-) (SL-CMP; Sca-1(lo) CMP) and a granulocyte/macrophage progenitor (GMP) is Sca-1(lo)lin(-)c-Kit(+)CD27(+)Flk-2(+)CD150(-/lo) (SL-GMP; Sca-1(lo) GMP). We found that mast cell progenitor potential is present in the SL-CMP fraction, but not in the more differentiated SL-GMP population, and is more closely related to megakaryocyte/erythrocyte specification. Our data provide criteria for the prospective isolation of SL-CMP and SL-GMP and support the conclusion that mast cells are specified during hematopoiesis earlier than and independently from granulocytes.
View details for DOI 10.1016/j.stem.2010.02.013
View details for Web of Science ID 000276823300014
View details for PubMedID 20362540
View details for PubMedCentralID PMC2852254
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The role of recipient mast cells in acute and chronic cardiac allograft rejection in C57BL/6-KitW-sh/W-sh mice
JOURNAL OF HEART AND LUNG TRANSPLANTATION
2010; 29 (4): 401-409
Abstract
Mast cells are hypothesized to promote rejection and adverse remodeling in cardiac allografts. In contrast, it has been reported that mast cells may enhance cardiac allograft survival in rats. We used C57BL/6-Kit(W-sh/W-sh) mast cell-deficient and corresponding wild-type mice to investigate possible contributions of recipient mast cells to acute or chronic cardiac allograft rejection.FVB (H-2(q); acute rejection), or C-H-2(bm12)KhEg (H-2(bm12); chronic rejection) donor hearts were heterotopically transplanted into C57BL/6-Kit(W-sh/W-sh) (H-2(b)) or C57BL/6-Kit(+/+) (H-2(b)) mice. The degree of acute rejection was assessed at 5 days and chronic rejection, at 52 days.In the acute rejection model, donor heart vascular cell adhesion molecule-1 (VCAM-1) expression was significantly lower in C57BL/6-Kit(W-sh/W-sh) than in wild-type recipients; however, acute rejection scores, graft survival, inflammatory cells, or cytokine expression did not differ significantly. In the chronic rejection model, the number of mast cells/mm(2) of allograft tissue was significantly increased 52 days after transplantation in allografts transplanted into C57BL/6-Kit(+/+) but not C57BL/6-Kit(W-sh/W-sh) mice; however, no substantial differences were noted in graft coronary artery disease, graft inflammatory cells, or levels of graft tissue expression of cytokines or adhesion molecules.Cardiac allografts undergoing chronic rejection in wild-type C57BL/6-Kit(+/+) mice exhibit increased numbers of mast cells, but acute or chronic cardiac allograft rejection can develop in C57BL/6-Kit(W-sh/W-sh) mice even though these recipients virtually lack mast cells. These findings indicate that recipient mast cells are not required for acute or chronic cardiac allograft rejection in the models examined.
View details for DOI 10.1016/j.healun.2009.08.019
View details for Web of Science ID 000276915100003
View details for PubMedID 19818646
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Evidence that vitamin D-3 promotes mast cell-dependent reduction of chronic UVB-nduced skin pathology in mice
JOURNAL OF EXPERIMENTAL MEDICINE
2010; 207 (3): 455-463
Abstract
Mast cell production of interleukin-10 (IL-10) can limit the skin pathology induced by chronic low-dose ultraviolet (UV)-B irradiation. Although the mechanism that promotes mast cell IL-10 production in this setting is unknown, exposure of the skin to UVB irradiation induces increased production of the immune modifying agent 1alpha,25-dihydroxyvitamin D(3) (1alpha,25[OH](2)D(3)). We now show that 1alpha,25(OH)(2)D(3) can up-regulate IL-10 mRNA expression and induce IL-10 secretion in mouse mast cells in vitro. To investigate the roles of 1alpha,25(OH)(2)D(3) and mast cell vitamin D receptor (VDR) expression in chronically UVB-irradiated skin in vivo, we engrafted the skin of genetically mast cell-deficient WBB6F(1)-Kit(W/W-v) mice with bone marrow-derived cultured mast cells derived from C57BL/6 wild-type or VDR(-/-) mice. Optimal mast cell-dependent suppression of the inflammation, local production of proinflammatory cytokines, epidermal hyperplasia, and epidermal ulceration associated with chronic UVB irradiation of the skin in Kit(W/W-v) mice required expression of VDR by the adoptively transferred mast cells. Our findings suggest that 1alpha,25(OH)(2)D(3)/VDR-dependent induction of IL-10 production by cutaneous mast cells can contribute to the mast cell's ability to suppress inflammation and skin pathology at sites of chronic UVB irradiation.
View details for DOI 10.1084/jem.20091725
View details for Web of Science ID 000275593900003
View details for PubMedID 20194632
View details for PubMedCentralID PMC2839149
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Mast Cell-Derived TNF Can Exacerbate Mortality during Severe Bacterial Infections in C57BL/6-KitW-sh/W-sh Mice
AMERICAN JOURNAL OF PATHOLOGY
2010; 176 (2): 926-938
Abstract
We used mast cell-engrafted genetically mast cell-deficient C57BL/6-Kit(W-sh/W-sh) mice to investigate the roles of mast cells and mast cell-derived tumor necrosis factor in two models of severe bacterial infection. In these mice, we confirmed findings derived from studies of mast cell-deficient WBB6F(1)-Kit(W/W-v) mice indicating that mast cells can promote survival in cecal ligation and puncture (CLP) of moderate severity. However, we found that the beneficial role of mast cells in this setting can occur independently of mast cell-derived tumor necrosis factor. By contrast, using mast cell-engrafted C57BL/6-Kit(W-sh/W-sh) mice, we found that mast cell-derived tumor necrosis factor can increase mortality during severe CLP and can also enhance bacterial growth and hasten death after intraperitoneal inoculation of Salmonella typhimurium. In WBB6F(1)-Kit(W-sh/W-sh) mice, mast cells enhanced survival during moderately severe CLP but did not significantly change the survival observed in severe CLP. Our findings in three types of genetically mast cell-deficient mice thus support the hypothesis that, depending on the circumstances (including mouse strain background, the nature of the mutation resulting in a mast cell deficiency, and type and severity of infection), mast cells can have either no detectable effect or opposite effects on survival during bacterial infections, eg, promoting survival during moderately severe CLP associated with low mortality but, in C57BL/6-Kit(W-sh/W-sh) mice, increasing mortality during severe CLP or infection with S. typhimurium.
View details for DOI 10.2353/ajpath.2010.090342
View details for Web of Science ID 000274111400040
View details for PubMedID 20035049
View details for PubMedCentralID PMC2808097
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Anaphylaxis: mechanisms of mast cell activation.
Chemical immunology and allergy
2010; 95: 45-66
Abstract
Anaphylaxis is a severe systemic allergic response that is rapid in onset and potentially lethal, and that typically is induced by an otherwise innocuous substance. In IgE-dependent and other examples of anaphylaxis, tissue mast cells and circulating basophilic granulocytes (basophils) are thought to represent major (if not the major) sources of the biologically active mediators that contribute to the pathology and, in unfortunate individuals, fatal outcome, of anaphylaxis. In this chapter, we will describe the mechanisms of mast cell (and basophil) activation in anaphylaxis, with a focus on IgE-dependent activation, which is thought to be responsible for most examples of antigen-induced anaphylaxis in humans. We will also discuss the use of mouse models to investigate the mechanisms that can contribute to anaphylaxis in that species in vivo, and the relevance of such mouse studies to human anaphylaxis.
View details for DOI 10.1159/000315937
View details for PubMedID 20519881
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Pillars article: fate of bone marrow-derived cultured mast cells after intracutaneous, intraperitoneal, and intravenous transfer into genetically mast cell-deficient w/wv mice. Evidence that cultured mast cells can give rise to both connective tissue type and mucosal mast cells.
Journal of immunology
2009; 183 (11): 6863-6881
View details for PubMedID 19923473
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Rabaptin-5 regulates receptor expression and functional activation in mast cells
BLOOD
2008; 112 (10): 4148-4157
Abstract
Rab5 is a small GTPase that regulates early endocytic events and is activated by RabGEF1/Rabex-5. Rabaptin-5, a Rab5 interacting protein, was identified as a protein critical for potentiating RabGEF1/Rabex-5's activation of Rab5. Using Rabaptin-5 shRNA knockdown, we show that Rabaptin-5 is dispensable for Rab5-dependent processes in intact mast cells, including high affinity IgE receptor (FcepsilonRI) internalization and endosome fusion. However, Rabaptin-5 deficiency markedly diminished expression of FcepsilonRI and beta1 integrin on the mast cell surface by diminishing receptor surface stability. This in turn reduced the ability of mast cells to bind IgE and significantly diminished both mast cell sensitivity to antigen (Ag)-induced mediator release and Ag-induced mast cell adhesion and migration. These findings show that, although dispensable for canonical Rab5 processes in mast cells, Rabaptin-5 importantly contributes to mast cell IgE-dependent immunologic function by enhancing mast cell receptor surface stability.
View details for DOI 10.1182/blood-2008-04-152660
View details for Web of Science ID 000260691300035
View details for PubMedID 18698003
View details for PubMedCentralID PMC2582003
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New developments in mast cell biology
NATURE IMMUNOLOGY
2008; 9 (11): 1215-1223
Abstract
Mast cells can function as effector and immunoregulatory cells in immunoglobulin E-associated allergic disorders, as well as in certain innate and adaptive immune responses. This review focuses on exciting new developments in the field of mast cell biology published in the past year. We highlight advances in the understanding of FcvarepsilonRI-mediated signaling and mast cell-activation events, as well as in the use of genetic models to study mast cell function in vivo. Finally, we discuss newly identified functions for mast cells or individual mast cell products, such as proteases and interleukin 10, in host defense, cardiovascular disease and tumor biology and in settings in which mast cells have anti-inflammatory or immunosuppressive functions.
View details for DOI 10.1038/ni.f.216
View details for Web of Science ID 000260248600008
View details for PubMedID 18936782
View details for PubMedCentralID PMC2856637
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IL-3 is required for increases in blood basophils in nematode infection in mice and can enhance IgE-dependent IL-4 production by basophils in vitro
LABORATORY INVESTIGATION
2008; 88 (11): 1134-1142
Abstract
Basophils represent potential effector and immunoregulatory cells, as well as a potential source of IL-4, during the immune response elicited by infection with the nematode Nippostrongylus brasiliensis (N.b.), and in other settings. However, the factors which regulate the numbers of blood basophils in mice, or the ability of these cells to produce IL-4, are not fully understood. We found that infection of mice with the nematodes N.b. or Strongyloides venezuelensis (S.v.) induced substantial increases in the numbers of blood basophils (to as high as 18% of circulating blood leukocytes). Experiments in IL-3-/- vs IL-3+/+ mice, and in IL-3-treated IL-3-/- mice, showed that essentially all of the increases in blood or bone marrow basophils during N.b. or S.v. infection were IL-3 dependent. Many of the blood, bone marrow or liver-derived basophils from IL-3-/- or IL-3+/+ mice expressed intracellular IL-4 upon stimulation with anti-IgE in vitro. However, after incubation of the cells with exogenous IgE in vitro, blood- or liver-derived basophils from IL-3+/+ mice exhibited higher levels of intracellular IL-4 after stimulation with anti-IgE than did basophils derived from IL-3-/- mice. Thus, IL-3 is a major regulator of the marked increases in blood basophil levels observed during infection of mice with N.b. or S.v. and also can enhance levels of intracellular IL-4 upon activation of basophils with anti-IgE in vitro.
View details for DOI 10.1038/labinvest.2008.88
View details for Web of Science ID 000260427600001
View details for PubMedID 18975389
View details for PubMedCentralID PMC2788437
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Mast cell-expressed orphan receptor CCRL2 binds chemerin and is required for optimal induction of IgE-mediated passive cutaneous anaphylaxis
JOURNAL OF EXPERIMENTAL MEDICINE
2008; 205 (10): 2207-2220
Abstract
Mast cells contribute importantly to both protective and pathological IgE-dependent immune responses. We show that the mast cell-expressed orphan serpentine receptor mCCRL2 is not required for expression of IgE-mediated mast cell-dependent passive cutaneous anaphylaxis but can enhance the tissue swelling and leukocyte infiltrates associated with such reactions in mice. We further identify chemerin as a natural nonsignaling protein ligand for both human and mouse CCRL2. In contrast to other "silent" or professional chemokine interreceptors, chemerin binding does not trigger ligand internalization. Rather, CCRL2 is able to bind the chemoattractant and increase local concentrations of bioactive chemerin, thus providing a link between CCRL2 expression and inflammation via the cell-signaling chemerin receptor CMKLR1.
View details for DOI 10.1084/jem.20080300
View details for Web of Science ID 000259656700005
View details for PubMedID 18794339
View details for PubMedCentralID PMC2556791
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The development of allergic inflammation
NATURE
2008; 454 (7203): 445-454
Abstract
Allergic disorders, such as anaphylaxis, hay fever, eczema and asthma, now afflict roughly 25% of people in the developed world. In allergic subjects, persistent or repetitive exposure to allergens, which typically are intrinsically innocuous substances common in the environment, results in chronic allergic inflammation. This in turn produces long-term changes in the structure of the affected organs and substantial abnormalities in their function. It is therefore important to understand the characteristics and consequences of acute and chronic allergic inflammation, and in particular to explore how mast cells can contribute to several features of this maladaptive pattern of immunological reactivity.
View details for DOI 10.1038/nature07204
View details for Web of Science ID 000257860300039
View details for PubMedID 18650915
View details for PubMedCentralID PMC3573758
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Immunomodulatory mast cells: negative, as well as positive, regulators of immunity
NATURE REVIEWS IMMUNOLOGY
2008; 8 (6): 478-U14
Abstract
Mast cells can promote inflammation and other tissue changes in IgE-associated allergic disorders, as well as in certain innate and adaptive immune responses that are thought to be independent of IgE. However, mast cells can also have anti-inflammatory and immunosuppressive functions. Here, we review the evidence that mast cells can have negative, as well as positive, immunomodulatory roles in vivo, and we propose that mast cells can both enhance and later suppress certain features of an immune response.
View details for DOI 10.1038/nri2327
View details for Web of Science ID 000256105700018
View details for PubMedID 18483499
View details for PubMedCentralID PMC2855166
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Neurotensin increases mortality and mast cells reduce neurotensin levels in a mouse model of sepsis
NATURE MEDICINE
2008; 14 (4): 392-398
Abstract
Sepsis is a complex, incompletely understood and often fatal disorder, typically accompanied by hypotension, that is considered to represent a dysregulated host response to infection. Neurotensin (NT) is a 13-amino-acid peptide that, among its multiple effects, induces hypotension. We find that intraperitoneal and plasma concentrations of NT are increased in mice after severe cecal ligation and puncture (CLP), a model of sepsis, and that mice treated with a pharmacological antagonist of NT, or NT-deficient mice, show reduced mortality during severe CLP. In mice, mast cells can degrade NT and reduce NT-induced hypotension and CLP-associated mortality, and optimal expression of these effects requires mast cell expression of neurotensin receptor 1 and neurolysin. These findings show that NT contributes to sepsis-related mortality in mice during severe CLP and that mast cells can lower NT concentrations, and suggest that mast cell-dependent reduction in NT levels contributes to the ability of mast cells to enhance survival after CLP.
View details for DOI 10.1038/nm1738
View details for Web of Science ID 000254674100025
View details for PubMedID 18376408
View details for PubMedCentralID PMC2873870
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Basophils are back!
IMMUNITY
2008; 28 (4): 495-497
Abstract
In this issue of Immunity, Tsujimura et al. (2008) report that the release of platelet-activating factor by basophils stimulated with immunoglobulin G1 (IgG1)-antigen immune complexes contributes substantially to the expression of an IgG1-dependent alternative pathway of systemic anaphylaxis in mice.
View details for DOI 10.1016/j.immuni.2008.03.010
View details for Web of Science ID 000254939400010
View details for PubMedID 18400194
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Skin mast cells enhance resistance to animal venoms
BLACKWELL PUBLISHING. 2008: 251
View details for Web of Science ID 000252897700069
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Mast cells: Versatile regulators of inflammation, tissue remodeling, host defense and homeostasis
JOURNAL OF DERMATOLOGICAL SCIENCE
2008; 49 (1): 7-19
Abstract
The possible roles of mast cells in heath and disease have been a topic of interest for over 125 years. Many adaptive or pathological processes affecting the skin or other anatomical sites have been associated with morphological evidence of mast cell activation, and/or with changes in mast cell numbers or phenotype. Such observations, taken together with the known functions of the diverse mediators, cytokines and growth factors which can be secreted by mast cells, have suggested many potential functions for mast cells in health and disease. Definitively identifying the importance of mast cells in biological responses in humans is difficult. However, mutant mice which are profoundly mast cell-deficient, especially those which can undergo engraftment with wild-type or genetically altered mast cells, provide an opportunity to investigate the importance of mast cells, and specific mast cell functions or products, in various adaptive or pathological responses in mice. Such work has shown that mast cells can significantly influence multiple features of inflammatory or immune responses, through diverse effects that can either promote or, surprisingly, suppress, aspects of these responses. Through such functions, mast cells can significantly influence inflammation, tissue remodeling, host defense and homeostasis.
View details for DOI 10.1016/j.jdermsci.2007.09.009
View details for Web of Science ID 000252523500003
View details for PubMedID 18024086
View details for PubMedCentralID PMC2788430
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IL-33 induces IL-13 production by mouse mast cells independently of IgE-Fc epsilon RI signals
JOURNAL OF LEUKOCYTE BIOLOGY
2007; 82 (6): 1481-1490
Abstract
The IL-1-related molecules, IL-1 and IL-18, can promote Th2 cytokine production by IgE/antigen-FcepsilonRI-stimulated mouse mast cells. Another IL-1-related molecule, IL-33, was identified recently as a ligand for T1/ST2. Although mouse mast cells constitutively express ST2, the effects of IL-33 on mast cell function are poorly understood. We found that IL-33, but not IL-1beta or IL-18, induced IL-13 and IL-6 production by mouse bone marrow-derived, cultured mast cells (BMCMCs) independently of IgE. In BMCMCs incubated with the potently cytokinergic SPE-7 IgE without specific antigen, IL-33, IL-1beta, and IL-18 each promoted IL-13 and IL-6 production, but the effects of IL-33 were more potent than those of IL-1beta or IL-18. IL-33 promoted cytokine production via a MyD88-dependent but Toll/IL-1R domain-containing adaptor-inducing IFN-beta-independent pathway. By contrast, IL-33 neither induced nor enhanced mast cell degranulation. At 200 ng/ml, IL-33 prolonged mast cell survival in the absence of IgE and impaired survival in the presence of SPE-7 IgE, whereas at 100 ng/ml, IL-33 had no effect on mast cell survival in the absence of IgE and reduced mast cell survival in the presence of IgE. These observations suggest potential roles for IL-33 in mast cell- and Th2 cytokine-associated immune responses and disorders.
View details for DOI 10.1189/jlb.0407200
View details for Web of Science ID 000251243800016
View details for PubMedID 17881510
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TIM-1 and TIM-3 enhancement of Th2 cytokine poduction by mast cells
BLOOD
2007; 110 (7): 2565-2568
Abstract
Members of the T-cell immunoglobulin- and mucin-domain-containing molecule (TIM) family have roles in T-cell-mediated immune responses. TIM-1 and TIM-2 are predominantly expressed on T helper type 2 (Th2) cells, whereas TIM-3 is preferentially expressed on Th1 and Th17 cells. We found that TIM-1 and TIM-3, but neither TIM-2 nor TIM-4, were constitutively expressed on mouse peritoneal mast cells and bone marrow-derived cultured mast cells (BMCMCs). After IgE + Ag stimulation, TIM-1 expression was down-regulated on BMCMCs, whereas TIM-3 expression was up-regulated. We also found that recombinant mouse TIM-4 (rmTIM-4), which is a ligand for TIM-1, as well as an anti-TIM-3 polyclonal Ab, can promote interleukin-4 (IL-4), IL-6, and IL-13 production without enhancing degranulation in BMCMCs stimulated with IgE + Ag. Moreover, the anti-TIM-3 Ab, but neither anti-TIM-1 Ab nor rmTIM-4, suppressed mast-cell apoptosis. These observations suggest that TIM-1 and TIM-3 may be able to influence T-cell-mediated immune responses in part through effects on mast cells.
View details for DOI 10.1182/blood-2006-11-058800
View details for Web of Science ID 000249800900056
View details for PubMedID 17620455
View details for PubMedCentralID PMC1988955
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IL-33 can promote survival, adhesion and cytokine production in human mast cells
LABORATORY INVESTIGATION
2007; 87 (10): 971-978
Abstract
IL-33 is a recently identified member of the IL-1 family of molecules, which also includes IL-1 and IL-18. IL-33 binds to the receptor, T1/ST2/IL-1R4, and can promote cytokine secretion by Th2 cells and NF-kappaB phosphorylation in mouse mast cells. However, the effects of these molecules, especially IL-33, in human mast cells are poorly understood. Expression of the receptors for IL-1 family molecules, specifically, IL-1R1, IL-18R and T1/ST2, was detectable intracellularly in human umbilical cord blood-derived mast cells (HUCBMCs) by flow cytometry, but was scarcely detectable on the cells' surface. However, IL-1beta, IL-18 or IL-33 induced phosphorylation of Erk, p38 and JNK in naïve HUCBMCs, and IL-33 or IL-1beta, but not IL-18, enhanced the survival of naive HUCBMCs and promoted their adhesion to fibronectin. IL-33 or IL-1beta also induced IL-8 and IL-13 production in naïve HUCBMCs, and enhanced production of these cytokines in IgE/anti-IgE-stimulated HUCBMCs, without enhancing secretion of either PGD(2) or histamine. Moreover, IL-33-mediated IL-8 production by HUCBMCs was markedly reduced by the p38 MAPK inhibitor, SB203580. In contrast to findings with mouse mast cells, IL-18 neither induced nor enhanced secretion of the mediators PGD(2) or histamine by HUCBMCs. Our findings identify previously unknown functions of IL-33 in human mast cells. One of these is that IL-33, like IL-1beta, can induce cytokine production in human mast cells even in the absence of stimuli of FcepsilonRI aggregation. Our findings thus support the hypothesis that IL-33 may enhance mast cell function in allergic disorders and other settings, either in the presence or absence of co-stimulation of mast cells via IgE/antigen-FcepsilonRI signals.
View details for DOI 10.1038/labinvest.3700663
View details for Web of Science ID 000249557400002
View details for PubMedID 17700564
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Mast cell-derived interleukin 10 limits skin pathology in contact dermatitis and chronic irradiation with ultraviolet B
NATURE IMMUNOLOGY
2007; 8 (10): 1095-1104
Abstract
Allergic contact dermatitis, such as in response to poison ivy or poison oak, and chronic low-dose ultraviolet B irradiation can damage the skin. Mast cells produce proinflammatory mediators that are thought to exacerbate these prevalent acquired immune or innate responses. Here we found that, unexpectedly, mast cells substantially limited the pathology associated with these responses, including infiltrates of leukocytes, epidermal hyperplasia and epidermal necrosis. Production of interleukin 10 by mast cells contributed to the anti-inflammatory or immunosuppressive effects of mast cells in these conditions. Our findings identify a previously unrecognized function for mast cells and mast cell-derived interleukin 10 in limiting leukocyte infiltration, inflammation and tissue damage associated with immunological or innate responses that can injure the skin.
View details for DOI 10.1038/ni1503
View details for Web of Science ID 000249691400024
View details for PubMedID 17767162
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Mast cell-derived TNF contributes to airway hyperreactivity, inflammation, and T(H)2 cytokine production in an asthma model in mice
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2007; 120 (1): 48-55
Abstract
Mast cells, IgE, and TNF, which have been implicated in human atopic asthma, contribute significantly to the allergic airway inflammation induced by ovalbumin (OVA) challenge in mice sensitized with OVA without alum. However, it is not clear to what extent mast cells represent a significant source of TNF in this mouse model.We investigated the importance of mast cell-derived TNF in a mast cell-dependent model of OVA-induced airway hyperreactivity (AHR) and allergic airway inflammation.Features of this model of airway inflammation were analyzed in C57BL/6J-wild-type mice, mast cell-deficient C57BL/6J-Kit(W-sh)(/W-sh) mice, and C57BL/6J Kit(W-sh/W-sh) mice that had been systemically engrafted with bone marrow-derived cultured mast cells from C57BL/6J-wild-type or C57BL/6J-TNF(-/-) mice.Ovalbumin-induced AHR and airway inflammation were significantly reduced in mast cell-deficient Kit(W-sh/W-sh) mice versus wild-type mice. By contrast, Kit(W-sh/W-sh) mice that had been engrafted with wild-type but not with TNF(-/-) bone marrow-derived cultured mast cells exhibited responses very similar to those observed in wild-type mice. Mast cells and mast cell-derived TNF were not required for induction of OVA-specific memory T cells in the sensitization phase, but significantly enhanced lymphocyte recruitment and T(H)2 cytokine production in the challenge phase.Mast cell-derived TNF contributes significantly to the pathogenesis of mast cell-dependent and IgE-dependent, OVA-induced allergic inflammation and AHR in mice, perhaps in part by enhancing lymphocyte recruitment and T(H)2 cytokine production.Our findings in mice support the hypothesis that mast cell-derived TNF can promote allergic inflammation and AHR in asthma.
View details for DOI 10.1016/j.jaci.2007.02.046
View details for Web of Science ID 000248066400007
View details for PubMedID 17482668
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Roles of RabGEF1/Rabex-5 domains in regulating Fc epsilon RI surface expression and Fc epsilon RI-dependent responses in mast cells
BLOOD
2007; 109 (12): 5308-5317
Abstract
RabGEF1/Rabex-5, a guanine nucleotide exchange factor (GEF) for the endocytic pathway regulator, Rab5, contains a Vps9 domain, an A20-like zinc finger (ZnF) domain, and a coiled coil domain. To investigate the importance of these domains in regulating receptor internalization and cell activation, we lentivirally delivered RabGEF1 mutants into RabGEF1-deficient (-/-) mast cells and examined Fc epsilon RI-dependent responses. Wild-type RabGEF1 expression corrected phenotypic abnormalities in -/- mast cells, including decreased basal Fc epsilon RI expression, slowed Fc epsilon RI internalization, elevated IgE + Ag-induced degranulation and IL-6 production, and the decreased ability of -/- cytosol to support endosome fusion. We showed that RabGEF1's ZnF domain has ubiquitin ligase activity. Moreover, the coiled coil domain of RabGEF1 is required for Rabaptin-5 binding and for maintaining basal levels of Rabaptin-5 and surface Fc epsilon RI. However, mutants lacking either of these domains normalized phenotypic abnormalities in IgE + antigen-activated -/- mast cells. By contrast, correction of these -/- phenotypes required a functional Vps9 domain. Thus, Fc epsilon RI-mediated mast cell functional activation is dependent on RabGEF1's GEF activity.
View details for DOI 10.1182/blood-2007-01-067363
View details for Web of Science ID 000247360200045
View details for PubMedID 17341663
View details for PubMedCentralID PMC1890836
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Mast cells in the promotion and limitation of chronic inflammation
IMMUNOLOGICAL REVIEWS
2007; 217: 304-328
Abstract
Observations of increased numbers of mast cells at sites of chronic inflammation have been reported for over a hundred years. Light and electron microscopic evidence of mast cell activation at such sites, taken together with the known functions of the diverse mediators, cytokines, and growth factors that can be secreted by appropriately activated mast cells, have suggested a wide range of possible functions for mast cells in promoting (or suppressing) many features of chronic inflammation. Similarly, these and other lines of evidence have implicated mast cells in a variety of adaptive or pathological responses that are associated with persistent inflammation at the affected sites. Definitively characterizing the importance of mast cells in chronic inflammation in humans is difficult. However, mice that genetically lack mast cells, especially those which can undergo engraftment with wildtype or genetically altered mast cells, provide a means to investigate the importance of mast cells and specific mast cell functions or products in diverse models of chronic inflammation. Such work has confirmed that mast cells can significantly influence multiple features of chronic inflammatory responses, through diverse effects that can either promote or, perhaps more surprisingly, suppress aspects of these responses.
View details for Web of Science ID 000246317100022
View details for PubMedID 17498068
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Mast cell-derived TNF can promote Th17 cell-dependent neutrophil recruitment in ovalbumin-challenged OTII mice
BLOOD
2007; 109 (9): 3640-3648
Abstract
Both mast cells and IL-17 can contribute to host defense and pathology in part by orchestrating neutrophil recruitment, but the possible role of mast cells in IL-17-induced inflammation remains to be defined. We found that mast cells and IL-17, but neither IFN-gamma nor FcRgamma signaling, contributed significantly to the antigen (Ag)-dependent airway neutrophilia elicited in ovalbumin-specific T-cell receptor (TCR)-expressing C57BL/6-OTII mice, and that IFN-gamma significantly suppressed IL-17-dependent airway neutrophilia in this setting. IL-18, IL-1beta, and TNF each contributed significantly to the development of Ag- and T helper 17 (Th17 cell)-mediated airway neutrophilia. Moreover, IL-17 enhanced mast cell TNF production in vitro, and mast cell-associated TNF contributed significantly to Ag- and Th17 cell-mediated airway neutrophilia in vivo. By contrast, we detected no significant role for the candidate mediators histamine, PGD(2), LTB(4), CXCL10, or IL-16, each of which can be produced by mast cells and other cell types, in the neutrophil infiltration elicited in this model. These findings establish that mast cells and mast cell-derived TNF can significantly enhance, by FcRgamma-independent mechanisms, the Ag- and Th17 cell-dependent development of a neutrophil-rich inflammatory response at a site of Ag challenge.
View details for DOI 10.1182/blood-2006-09-046128
View details for Web of Science ID 000246091400014
View details for PubMedID 17197430
View details for PubMedCentralID PMC1874568
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TNF can contribute to multiple features of ovalbumin-induced allergic inflammation of the airways in mice
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2007; 119 (3): 680-686
Abstract
TNF is thought to contribute to airway hyperreactivity (AHR) and airway inflammation in asthma. However, studies with TNF-deficient or TNF receptor-deficient mice have not produced a clear picture of the role of TNF in the AHR associated with allergic inflammation in the mouse.We used a genetic approach to investigate the contributions of TNF to antigen-induced AHR and airway inflammation in mice on the C57BL/6 background.We analyzed features of airway allergic inflammation, including antigen-induced AHR, in C57BL/6 wild-type and TNF(-/-) mice, using 2 different methods for sensitizing the mice to ovalbumin (OVA).In mice sensitized to OVA administered with the adjuvant aluminum hydroxide (alum), which develop IgE-independent and mast cell-independent allergic inflammation and AHR, we found no significant differences in OVA-induced AHR in C57BL/6-TNF(-/-) versus wild-type mice. By contrast, in mice sensitized to OVA without alum, which develop allergic inflammation that is significantly mast cell-dependent, C57BL/6-TNF(-/-) mice exhibited significant reductions versus wild-type mice in OVA-induced AHR to methacholine; numbers of lymphocytes, neutrophils, and eosinophils in bronchoalveolar lavage fluid; levels of myeloperoxidase, eosinophil peroxidase, and the cytokines IL-4, IL-5, and IL-17 in lung tissue; and histologic evidence of pulmonary inflammation.In pulmonary allergic inflammation induced in mice immunized with OVA without alum, TNF significantly contributes to several features of the response, including antigen-induced inflammation and AHR.Our findings in mice support the hypothesis that TNF can promote the allergic inflammation and AHR associated with asthma.
View details for DOI 10.1016/j.jaci.2006.11.701
View details for Web of Science ID 000244925000022
View details for PubMedID 17336618
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Effector and potential immunoregulatory roles of mast cells in IgE-associated acquired immune responses
CURRENT OPINION IN IMMUNOLOGY
2006; 18 (6): 751-760
Abstract
Mast cells are best known as critical effector cells in anaphylaxis and other examples of IgE-associated immediate hypersensitivity reactions. However, mast cells also can contribute to the development of the late-phase responses that occur in some sensitized subjects hours after initial exposure to specific antigen, and can promote many of the features of chronic allergic inflammation, including tissue remodeling and functional changes in the affected organs. In addition to such effector cell functions in IgE-associated immune responses, recent evidence indicates that mast cells can importantly influence the sensitization phase of at least some acquired immune responses, and can contribute to the pathology of autoimmune disorders and to the expression of peripheral tolerance.
View details for DOI 10.1016/j.coi.2006.09.011
View details for Web of Science ID 000242036900018
View details for PubMedID 17011762
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Mast cell-derived tumor necrosis factor can promote nerve fiber elongation in the skin during contact hypersensitivity in mice
AMERICAN JOURNAL OF PATHOLOGY
2006; 169 (5): 1713-1721
Abstract
In humans, lesions of contact eczema or atopic dermatitis can exhibit increases in epidermal nerves, but the mechanism resulting in such nerve elongation are not fully understood. We found that contact hypersensitivity reactions to oxazolone in mice were associated with significant increases in the length of nerves in the epidermis and dermis. Using genetically mast cell-deficient c-kit mutant mice selectively repaired of their dermal mast cell deficiency with either wild-type or tumor necrosis factor (TNF)-deficient mast cells, we found that mast cells, and mast cell-derived TNF, significantly contributed to the elongation of epidermal and dermal PGP 9.5+ nerves and dermal CGRP+ nerves, as well as to the inflammation observed at sites of contact hypersensitivity in response to oxazolone. Moreover, the percentage of mast cells in close proximity to dermal PGP 9.5+ nerve fibers was significantly higher in wild-type mice and in c-kit mutant mice repaired of their dermal mast cell deficiency by the adoptive transfer of wild-type mast cells than in TNF-deficient mice or in TNF-/- mast cell-engrafted c-kit mutant mice. These observations show that mast cells, and mast cell-derived TNF, can promote the elongation of cutaneous nerve fibers during contact hypersensitivity in the mouse.
View details for DOI 10.2353/ajpath.2006.060602
View details for Web of Science ID 000241603700019
View details for PubMedID 17071594
View details for PubMedCentralID PMC1780201
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Mast cells can enhance resistance to snake and honeybee venoms
SCIENCE
2006; 313 (5786): 526-530
Abstract
Snake or honeybee envenomation can cause substantial morbidity and mortality, and it has been proposed that the activation of mast cells by snake or insect venoms can contribute to these effects. We show, in contrast, that mast cells can significantly reduce snake-venom-induced pathology in mice, at least in part by releasing carboxypeptidase A and possibly other proteases, which can degrade venom components. Mast cells also significantly reduced the morbidity and mortality induced by honeybee venom. These findings identify a new biological function for mast cells in enhancing resistance to the morbidity and mortality induced by animal venoms.
View details for DOI 10.1126/science.1128877
View details for Web of Science ID 000239308600064
View details for PubMedID 16873664
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Mast cells can promote the development of multiple features of chronic asthma in mice
JOURNAL OF CLINICAL INVESTIGATION
2006; 116 (6): 1633-1641
Abstract
Bronchial asthma, the most prevalent cause of significant respiratory morbidity in the developed world, typically is a chronic disorder associated with long-term changes in the airways. We developed a mouse model of chronic asthma that results in markedly increased numbers of airway mast cells, enhanced airway responses to methacholine or antigen, chronic inflammation including infiltration with eosinophils and lymphocytes, airway epithelial goblet cell hyperplasia, enhanced expression of the mucin genes Muc5ac and Muc5b, and increased levels of lung collagen. Using mast cell-deficient (Kit(W-sh/W-sh) and/or Kit(W/W-v)) mice engrafted with FcRgamma+/+ or FcRgamma-/- mast cells, we found that mast cells were required for the full development of each of these features of the model. However, some features also were expressed, although usually at less than wild-type levels, in mice whose mast cells lacked FcRgamma and therefore could not be activated by either antigen- and IgE-dependent aggregation of Fc epsilonRI or the binding of antigen-IgG1 immune complexes to Fc gammaRIII. These findings demonstrate that mast cells can contribute to the development of multiple features of chronic asthma in mice and identify both Fc Rgamma-dependent and Fc Rgamma-independent pathways of mast cell activation as important for the expression of key features of this asthma model.
View details for DOI 10.1172/JCI25702
View details for Web of Science ID 000237979700025
View details for PubMedID 16710480
View details for PubMedCentralID PMC1462940
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Mast cell-associated TNF promotes dendritic cell migration
JOURNAL OF IMMUNOLOGY
2006; 176 (7): 4102-4112
Abstract
Mast cells represent a potential source of TNF, a mediator which can enhance dendritic cell (DC) migration. Although the importance of mast cell-associated TNF in regulating DC migration in vivo is not clear, mast cells and mast cell-derived TNF can contribute to the expression of certain models of contact hypersensitivity (CHS). We found that CHS to FITC was significantly impaired in mast cell-deficient Kit(W-sh/W-sh) or TNF(-/)(-) mice. The reduced expression of CHS in Kit(W-sh/W-sh) mice was fully repaired by local transfer of wild-type bone marrow-derived cultured mast cells (BMCMCs), but was only partially repaired by transfer of TNF(-/)(-) BMCMCs. Thus, mast cells, and mast cell-derived TNF, were required for optimal expression of CHS to FITC. We found that the migration of FITC-bearing skin DCs into draining lymph nodes (LNs) 24 h after epicutaneous administration of FITC in naive mice was significantly reduced in mast cell-deficient or TNF(-/)(-) mice, but levels of DC migration in these mutant mice increased to greater than wild-type levels by 48 h after FITC sensitization. Mast cell-deficient or TNF(-/)(-) mice also exhibited significantly reduced migration of airway DCs to local LNs at 24 h after intranasal challenge with FITC-OVA. Migration of FITC-bearing DCs to LNs draining the skin or airways 24 h after sensitization was repaired in Kit(W-sh/W-sh) mice which had been engrafted with wild-type but not TNF(-/)(-) BMCMCs. Our findings indicate that mast cell-associated TNF can contribute significantly to the initial stages of FITC-induced migration of cutaneous or airway DCs.
View details for Web of Science ID 000238769300035
View details for PubMedID 16547246
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RabGEF1 regulates stem cell factor/c-Kit-mediated signaling events and biological responses in mast cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (8): 2659-2664
Abstract
We recently reported that RabGEF1 is a negative regulator of high-affinity Fc receptor for IgE (Fc epsilonRI)-dependent mast cell activation and that mice lacking RabGEF1 develop severe skin inflammation and increased numbers of dermal mast cells. To better understand how RabGEF1 can regulate signaling events and biological responses in mast cells, we examined the responses of bone marrow-derived cultured mast cells (BMCMCs) from wild-type (+/+) and Rabgef1 knockout (-/-) mice after stimulation with the c-Kit ligand, stem cell factor (SCF), an important regulator of mast cell development, survival, proliferation, and activation. We found that RabGEF1-deficient mast cells exhibited enhanced and prolonged activation of Ras and extracellular regulated kinase, and significantly elevated IL-6 secretion, after stimulation with SCF. SCF-induced activation of c-Jun N-terminal kinase was increased in Rabgef1-/- BMCMCs, but without corresponding significant increases in SCF-induced migration or adhesion. SCF-mediated activation of the survival-enhancing kinase, Akt, also was increased in Rabgef1-/- BMCMCs, and these cells had a survival advantage over their +/+ counterparts in vitro. Despite enhanced Ras activation in the absence of RabGEF1, SCF-induced proliferation was lower in Rabgef1-/- BMCMCs compared with their +/+ counterparts. Finally, we found that c-Kit internalization was delayed in the absence of RabGEF1, probably reflecting a positive role for RabGEF1 in the regulation of endocytic events, and that infection of Rabgef1-/- BMCMCs with a wild-type RabGEF1 lentiviral construct normalized c-Kit internalization to the levels seen in +/+ BMCMCs. Thus, RabGEF1 plays a critical role in the regulation of SCF/c-Kit-mediated signaling events and biological responses in mast cells.
View details for Web of Science ID 000235554900034
View details for PubMedID 16533754
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Mast cells enhance T cell activation: Importance of mast cell costimulatory molecules and secreted TNF
JOURNAL OF IMMUNOLOGY
2006; 176 (4): 2238-2248
Abstract
We recently reported that mast cells stimulated via FcepsilonRI aggregation can enhance T cell activation by a TNF-dependent mechanism. However, the molecular mechanisms responsible for such IgE-, Ag- (Ag-), and mast cell-dependent enhancement of T cell activation remain unknown. In this study we showed that mouse bone marrow-derived cultured mast cells express various costimulatory molecules, including members of the B7 family (ICOS ligand (ICOSL), PD-L1, and PD-L2) and the TNF/TNFR families (OX40 ligand (OX40L), CD153, Fas, 4-1BB, and glucocorticoid-induced TNFR). ICOSL, PD-L1, PD-L2, and OX40L also are expressed on APCs such as dendritic cells and can modulate T cell function. We found that IgE- and Ag-dependent mast cell enhancement of T cell activation required secreted TNF; that TNF can increase the surface expression of OX40, ICOS, PD-1, and other costimulatory molecules on CD3(+) T cells; and that a neutralizing Ab to OX40L, but not neutralizing Abs to ICOSL or PD-L1, significantly reduced IgE/Ag-dependent mast cell-mediated enhancement of T cell activation. These results indicate that the secretion of soluble TNF and direct cell-cell interactions between mast cell OX40L and T cell OX40 contribute to the ability of IgE- and Ag-stimulated mouse mast cells to enhance T cell activation.
View details for Web of Science ID 000235180900025
View details for PubMedID 16455980
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Second symposium on the definition and management of anaphylaxis: summary report--Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium.
journal of allergy and clinical immunology
2006; 117 (2): 391-397
Abstract
There is no universal agreement on the definition of anaphylaxis or the criteria for diagnosis. In July 2005, the National Institute of Allergy and Infectious Disease and Food Allergy and Anaphylaxis Network convened a second meeting on anaphylaxis, which included representatives from 16 different organizations or government bodies, including representatives from North America, Europe, and Australia, to continue working toward a universally accepted definition of anaphylaxis, establish clinical criteria that would accurately identify cases of anaphylaxis with high precision, further review the evidence on the most appropriate management of anaphylaxis, and outline the research needs in this area.
View details for PubMedID 16461139
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A key regulatory role for histamine in experimental autoimmune encephalomyelitis: Disease exacerbation in histidine decarboxylase-deficient mice
JOURNAL OF IMMUNOLOGY
2006; 176 (1): 17-26
Abstract
Histamine can modulate the cytokine network and influence Th1 and Th2 balance and Ab-isotype switching. Thus, pharmacological blockade or genetic deletion of specific histamine receptors has been shown to reduce the severity of experimental autoimmune encephalomyelitis (EAE), a prototypic Th1-mediated disease with similarities to human multiple sclerosis. To study the comprehensive contribution of endogenous histamine to the expression of EAE, we attempted to induce EAE in histidine decarboxylase-deficient mice, which are genetically unable to make histamine. In this study, we show that EAE is significantly more severe in HDC-/-, histamine-deficient mice, with diffuse inflammatory infiltrates, including a prevalent granulocytic component, in the brain and cerebellum. Unlike splenocytes from wild-type mice, splenocytes from HDC-/- mice do not produce histamine in response to the myelin Ag, whereas production of IFN-gamma, TNF, and leptin are increased in HDC-/- splenocytes in comparison to those from wild-type mice. Endogenous histamine thus appears to regulate importantly the autoimmune response against myelin and the expression of EAE, in this model, and to limit immune damage to the CNS. Understanding which receptor(s) for histamine is/are involved in regulating autoimmunity against the CNS might help in the development of new strategies of treatment for EAE and multiple sclerosis.
View details for Web of Science ID 000234262600005
View details for PubMedID 16365391
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Pathways of anaphylaxis to self myelin peptides in mice.
ACADEMIC PRESS INC ELSEVIER SCIENCE. 2006: S119
View details for DOI 10.1016/j.clim.2006.04.273
View details for Web of Science ID 000237924300315
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Monomeric IgE enhances human mast cell chemokine production: ILA-4 augments and dexamethasone suppresses the response
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2005; 116 (6): 1357-1363
Abstract
Mouse monoclonal IgE antibodies can promote the survival of mouse bone marrow-derived cultured mast cells and induce the cells to secrete mediators in the absence of known specific antigen.To determine whether human IgE, in the absence of known specific antigen, had effects on the mediator secretion or survival of human mast cells.We tested whether human IgE induced human cord blood-derived mast cells to secrete mediators or enhanced their survival on withdrawal of stem cell factor.Exposure to IgE, but not IgG, at concentrations as low as 2.5 microg/mL significantly enhanced the release of IL-8 and monocyte chemoattractant protein 1, but not histamine or cysteinyl leukotrienes. However, under the conditions tested, chemokine production in response to IgE alone was significantly less than that induced when aliquots of the same IgE-sensitized populations of human mast cells were stimulated with anti-IgE. The production of IL-8 and monocyte chemoattractant protein 1 in response to either IgE alone or IgE and anti-IgE was enhanced by preincubation of the cells in IL-4 and was inhibited by preincubation of the cells with dexamethasone. By contrast, we did not detect any ability of IgE to enhance mast cell survival on withdrawal of stem cell factor.Exposure to human IgE in vitro in the absence of known specific antigen can enhance chemokine production by human mast cells, and this secretory response can be enhanced by preincubation of the mast cells with IL-4 and can be suppressed by dexamethasone.
View details for DOI 10.1016/j.jaci.2005.08.042
View details for Web of Science ID 000235687000030
View details for PubMedID 16337471
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Activity of the tyrosine kinase inhibitor PKC412 in a patient with mast cell leukemia with the D816V KIT mutation
BLOOD
2005; 106 (8): 2865-2870
Abstract
The majority of patients with systemic mast cell disease express the imatinib-resistant Asp816Val (D816V) mutation in the KIT receptor tyrosine kinase. Limited treatment options exist for aggressive systemic mastocytosis (ASM) and mast cell leukemia (MCL). We evaluated whether PKC412, a small-molecule inhibitor of KIT with a different chemical structure from imatinib, may have therapeutic use in advanced SM with the D816V KIT mutation. We treated a patient with MCL (with an associated myelodysplastic syndrome (MDS)/myeloproliferative disorder [MPD]) based on in vitro studies demonstrating that PKC412 could inhibit D816V KIT-transformed Ba/F3 cell growth with a 50% inhibitory concentration (IC50) of 30 nM to 40 nM. The patient exhibited a partial response with significant resolution of liver function abnormalities. In addition, PKC412 treatment resulted in a significant decline in the percentage of peripheral blood mast cells and serum histamine level and was associated with a decrease in KIT phosphorylation and D816V KIT mutation frequency. The patient died after 3 months of therapy due to progression of her MDS/MPD to acute myeloid leukemia (AML). This case indicates that KIT tyrosine kinase inhibition is a feasible approach in SM, but single-agent clinical efficacy may be limited by clonal evolution in the advanced leukemic phase of this disease.
View details for DOI 10.1182/blood-2005-04-1568
View details for PubMedID 15972446
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Mast cell-deficient W-sash c-kit mutant Kit(W-sh/W-sh) mice as a model for investigating mast cell biology in vivo
AMERICAN JOURNAL OF PATHOLOGY
2005; 167 (3): 835-848
Abstract
Mice carrying certain mutations in the white spotting (W) locus (ie, c-kit) exhibit reduced c-kit tyrosine kinase-dependent signaling that results in mast cell deficiency and other phenotypic abnormalities. The c-kit mutations in Kit(W/W-v) mice impair melanogenesis and result in anemia, sterility, and markedly reduced levels of tissue mast cells. In contrast, Kit(W-sh/W-sh) mice, bearing the W-sash (W(sh)) inversion mutation, have mast cell deficiency but lack anemia and sterility. We report that adult Kit(W-sh/W-sh) mice had a profound deficiency in mast cells in all tissues examined but normal levels of major classes of other differentiated hematopoietic and lymphoid cells. Unlike Kit(W/W-v) mice, Kit(W-sh/W-sh) mice had normal numbers of TCR gammadelta intraepithelial lymphocytes in the intestines and did not exhibit a high incidence of idiopathic dermatitis, ulcers, or squamous papillomas of the stomach, but like Kit(W/W-v) mice, they lacked interstitial cells of Cajal in the gut and exhibited bile reflux into the stomach. Systemic or local reconstitution of mast cell populations was achieved in nonirradiated adult Kit(W-sh/W-sh) mice by intravenous, intraperitoneal, or intradermal injection of wild-type bone marrow-derived cultured mast cells but not by transplantation of wild-type bone marrow cells. Thus, Kit(W-sh/W-sh) mice represent a useful model for mast cell research, especially for analyzing mast cell function in vivo.
View details for Web of Science ID 000231514500018
View details for PubMedID 16127161
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Identification of mast cell progenitors in adult mice
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2005; 102 (32): 11408-11413
Abstract
It is well known that mast cells are derived from hematopoietic stem cells. However, in adult hematopoiesis, a committed mast cell progenitor has not yet been identified in any species, nor is it clear at what point during adult hematopoiesis commitment to the mast cell lineage occurs. We identified a cell population in adult mouse bone marrow, characterized as Lin(-)c-Kit(+)Sca-1(-)-Ly6c(-)FcepsilonRIalpha(-)CD27(-)beta7(+)T1/ST2+, that gives rise only to mast cells in culture and that can reconstitute the mast cell compartment when transferred into c-kit mutant mast cell-deficient mice. In addition, our experiments strongly suggest that these adult mast cell progenitors are derived directly from multipotential progenitors instead of, as previously proposed, common myeloid progenitors or granulocyte/macrophage progenitors.
View details for DOI 10.1073/pnas.0504197102
View details for Web of Science ID 000231253400051
View details for PubMedID 16006518
View details for PubMedCentralID PMC1183570
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Mast cells enhance T cell activation: Importance of mast cell-derived TNF
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2005; 102 (18): 6467-6472
Abstract
Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcepsilonRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production.
View details for DOI 10.1073/pnas.0501912102
View details for Web of Science ID 000228918400041
View details for PubMedID 15840716
View details for PubMedCentralID PMC1088381
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Symposium on the definition and management of anaphylaxis: Summary report
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2005; 115 (3): 584-591
View details for DOI 10.1016/j.jaci.2005.01.008
View details for Web of Science ID 000227687000023
View details for PubMedID 15753908
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Decreased susceptibility of mast cell-deficient Kit(W)/Kit(W-v) mice to the development of 1,2-dimethylhydrazine-induced intestinal tumors
LABORATORY INVESTIGATION
2005; 85 (3): 388-396
Abstract
Administration of 1,2-dimethylhydrazine (DMH) induces intestinal epithelial tumors in mice. Increased numbers of mast cells have been reported to occur both within and near a variety of different neoplasms, including DMH-induced intestinal tumors. We investigated the role of the tyrosine kinase receptor, c-kit, and mast cells, in this model by administering DMH to c-kit mutant mast cell-deficient mice and the congenic normal mice. We attempted to induce colonic tumors by administering DMH (20 mg/kg body weight, s.c., weekly for 20 weeks) to WBB6F1-Kit+/+ (+/+) wild-type mice, the congenic mast cell-deficient WBB6F1-Kit(W)/Kit(W-v) (W/W(v)) mice and W/W(v) mice that had been repaired of their mast cell deficiency by adoptive transfer of bone marrow cells derived from the congenic +/+ mice. The susceptibility to the development of DMH-induced colonic tumors, and the numbers of mast cells associated with these tumors, was evaluated. Normal (+/+) mice exhibited significantly higher numbers of mast cells in DMH-induced intestinal tumors than in macroscopically normal colonic mucosa. Treatment with DMH induced development of colonic tumors in 97% of +/+ mice, but in only 32% of the W/W(v) mice. W/W(v) mice that had been repaired of their mast cell deficiency by transfer of +/+ bone marrow cells expressed susceptibility to the development of colonic tumors that was similar to that of wild-type mice. These results show that genetic impairment of c-kit function reduces the susceptibility of mice to DMH-induced colonic tumors, and that defects in bone marrow-derived cells in the W/W(v) mice contribute significantly to this result. Our findings also are consistent with the possibility that mast cells promote the development of DMH-induced colonic epithelial tumors in mice.
View details for DOI 10.1038/labinvest.3700232
View details for Web of Science ID 000227168700009
View details for PubMedID 15696191
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Pathogenesis and management of anaphylaxis: Current status and future challenges
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2005; 115 (3): 571-574
View details for DOI 10.1016/j.jaci.2004.12.1133
View details for Web of Science ID 000227687000021
View details for PubMedID 15753906
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Mast cells in the development of adaptive immune responses
NATURE IMMUNOLOGY
2005; 6 (2): 135-142
Abstract
Mast cells are so widely recognized as critical effector cells in allergic disorders and other immunoglobulin E-associated acquired immune responses that it can be difficult to think of them in any other context. However, mast cells also can be important as initiators and effectors of innate immunity. In addition, mast cells that are activated during innate immune responses to pathogens, or in other contexts, can secrete products and have cellular functions with the potential to facilitate the development, amplify the magnitude or regulate the kinetics of adaptive immune responses. Thus, mast cells may influence the development, intensity and duration of adaptive immune responses that contribute to host defense, allergy and autoimmunity, rather than simply functioning as effector cells in these settings.
View details for DOI 10.1038/ni1158
View details for Web of Science ID 000226468100016
View details for PubMedID 15662442
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Mast cells as "tunable" effector and immunoregulatory cells: Recent advances
ANNUAL REVIEW OF IMMUNOLOGY
2005; 23: 749-786
Abstract
This review focuses on recent progress in our understanding of how mast cells can contribute to the initiation, development, expression, and regulation of acquired immune responses, both those associated with IgE and those that are apparently expressed independently of this class of Ig. We emphasize findings derived from in vivo studies in mice, particularly those employing genetic approaches to influence mast cell numbers and/or to alter or delete components of pathways that can regulate mast cell development, signaling, or function. We advance the hypothesis that mast cells not only can function as proinflammatory effector cells and drivers of tissue remodeling in established acquired immune responses, but also may contribute to the initiation and regulation of such responses. That is, we propose that mast cells can also function as immunoregulatory cells. Finally, we show that the notion that mast cells have primarily two functional configurations, off (or resting) or on (or activated for extensive mediator release), markedly oversimplifies reality. Instead, we propose that mast cells are "tunable," by both genetic and environmental factors, such that, depending on the circumstances, the cell can be positioned phenotypically to express a wide spectrum of variation in the types, kinetics, and/or magnitude of its secretory functions.
View details for DOI 10.1146/annurev.immunol.21.120601.141025
View details for Web of Science ID 000228947000022
View details for PubMedID 15771585
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RabGEF1, a negative regulator of Ras signalling, mast cell activation and skin inflammation.
Novartis Foundation symposium
2005; 271: 115-124
Abstract
Mast cell activation induced by the aggregation of FcepsilonRI with IgE and antigen is mediated through the activation of multiple protein kinase cascades. This process induces mast cells to undergo degranulation, to synthesize and release lipid mediators, and to secrete multiple cytokines, chemokines and growth factors. We found that RabGEF1 (Rabex-5) binds to Ras and negatively regulates Ras activation and downstream effector pathways during FcepsilonRI-dependent mouse mast cell activation. Mast cells derived from RabGEF1-deficient mice exhibit significantly enhanced levels of degranulation, release of lipid mediators and secretion of cytokines in response to FcepsilonRI aggregation. RabGEF1 knockout mice have increased perinatal mortality and the mice that do survive develop severe skin inflammation and increased numbers of mast cells in the dermis, some of which exhibit morphological evidence of degranulation. These mice also show elevated concentrations of serum histamine and IgE. Thus, RabGEF1 is a negative regulator of Ras signalling and FcepsilonRI-dependent mast cell activation in vitro, and a lack of RabGEF1 results in the development of elevated numbers of mast cells in the skin and severe skin inflammation in vivo.
View details for PubMedID 16605131
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Mast cells promote homeostasis by limiting endothelin-1-induced toxicity
NATURE
2004; 432 (7016): 512-516
Abstract
Endothelin-1 (ET-1) is a 21-amino-acid peptide, derived from vascular endothelial cells, with potent vasoconstrictor activity. ET-1 has been implicated in diverse physiological or pathological processes, including the vascular changes associated with sepsis. However, the factors that regulate ET-1-associated toxicity during bacterial infections, or in other settings, are not fully understood. Both the pathology associated with certain allergic and autoimmune disorders, and optimal host defence against bacterial and parasitic infections are mediated by mast cells. In vitro, mast cells can produce ET-1 (ref. 11), undergo ET-1-dependent and endothelin-A receptor (ET(A))-dependent activation, and release proteases that degrade ET-1 (ref. 14). Although the potential relationships between mast cells and the ET-1 system thus may be complex, the importance of interactions between ET-1 and mast cells in vivo is obscure. Here we show that ET(A)-dependent mast-cell activation can diminish both ET-1 levels and ET-1-induced pathology in vivo, and also can contribute to optimal survival during acute bacterial peritonitis. These findings identify a new biological function for mast cells: promotion of homeostasis by limiting the toxicity associated with an endogenous mediator.
View details for DOI 10.1038/nature03085
View details for Web of Science ID 000225322100049
View details for PubMedID 15543132
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RabGEF1 is a negative regulator of mast cell activation and skin inflammation
NATURE IMMUNOLOGY
2004; 5 (8): 844-852
Abstract
Mast cell activation induced by aggregation of Fc epsilon RI receptors with immunoglobulin E and antigen is mediated through the activation of multiple protein kinase cascades. Here we report that the regulatory protein RabGEF1 bound to Ras and negatively regulated Ras activation and its 'downstream' effector pathways in Fc epsilon RI-dependent mast cell activation. RabGEF1-deficient mast cells showed enhanced degranulation and release of lipid mediators and cytokines in response to Fc epsilon RI aggregation. RabGEF1-deficient mice developed severe skin inflammation and had increased numbers of mast cells. Thus, RabGEF1 is a negative regulator of Fc epsilon RI-dependent mast cell activation, and a lack of RabGEF1 results in the development of skin inflammation in vivo.
View details for DOI 10.1038/ni1093
View details for Web of Science ID 000222955600016
View details for PubMedID 15235600
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Immune sensitization in the skin is enhanced by antigen-independent effects of IgE
IMMUNITY
2004; 20 (4): 381-392
Abstract
Contact sensitivity responses require both effective immune sensitization following cutaneous exposure to chemical haptens and antigen-specific elicitation of inflammation upon subsequent hapten challenge. We report that antigen-independent effects of IgE antibodies can promote immune sensitization to haptens in the skin. Contact sensitivity was markedly impaired in IgE(-/-) mice but was restored by either transfer of sensitized cells from wild-type mice or administration of hapten-irrelevant IgE before sensitization. Moreover, IgE(-/-) mice exhibited impairment in the reduction of dendritic cell numbers in the epidermis after hapten exposure. Monomeric IgE has been reported to influence mast cell function. We observed diminished contact sensitivity in mice lacking FcepsilonRI or mast cells, and mRNA for several mast cell-associated genes was reduced in IgE(-/-) versus wild-type skin after hapten exposure. We speculate that levels of IgE normally present in mice favor immune sensitization via antigen-independent but FcepsilonRI-dependent effects on mast cells.
View details for Web of Science ID 000221442800005
View details for PubMedID 15084268
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Chair's introduction. Anaphylaxis.
Novartis Foundation symposium
2004; 257: 1-5
View details for PubMedID 15025388
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Evidence that IgE molecules mediate a spectrum of effects on mast cell survival and activation via aggregation of the Fc epsilon RI
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2003; 100 (22): 12911-12916
Abstract
We demonstrate that binding of different IgE molecules (IgEs) to their receptor, FcepsilonRI, induces a spectrum of activation events in the absence of a specific antigen and provide evidence that such activation reflects aggregation of FcepsilonRI. Highly cytokinergic IgEs can efficiently induce production of cytokines and render mast cells resistant to apoptosis in an autocrine fashion, whereas poorly cytokinergic IgEs induce these effects inefficiently. Highly cytokinergic IgEs seem to induce more extensive FcepsilonRI aggregation than do poorly cytokinergic IgEs, which leads to stronger mast cell activation and survival effects. These effects of both types of IgEs require Syk tyrosine kinase and can be inhibited by FcepsilonRI disaggregation with monovalent hapten. In hybridoma-transplanted mice, mucosal mast cell numbers correlate with serum IgE levels. Therefore, survival effects of IgE could contribute to the pathogenesis of allergic disease.
View details for DOI 10.1073/pnas.1735525100
View details for Web of Science ID 000186301100073
View details for PubMedID 14569021
View details for PubMedCentralID PMC240718
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Involvement of both 'allergic' and "autoimmune' mechanisms in EAE, MS and other autoimmune diseases
TRENDS IN IMMUNOLOGY
2003; 24 (9): 479-484
View details for DOI 10.1016/S1471-4906(03)00233-3
View details for Web of Science ID 000185450200008
View details for PubMedID 12967671
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Identification of A(3) receptor- and mast cell-dependent and -independent components of adenosine-mediated airway responsiveness in mice
JOURNAL OF IMMUNOLOGY
2003; 171 (1): 331-337
Abstract
Adenosine-induced bronchoconstriction is a well-recognized feature of atopic asthma. Adenosine acts through four different G protein-coupled receptors to produce a myriad of physiological effects. To examine the contribution of the A(3) adenosine receptor to adenosine-induced bronchoconstriction and to assess the contribution of mast cells to this process, we quantified airway responsiveness to aerosolized adenosine in wild-type, A(3) receptor-deficient, and mast cell-deficient mice. Compared with the robust airway responses elicited by adenosine in wild-type mice, both A(3)-deficient and mast cell-deficient mice exhibited a significantly attenuated response compared with their respective wild-type controls. Histological examination of the airways 4 h after adenosine exposure revealed extensive degranulation of airway mast cells as well as infiltration of neutrophils in wild-type mice, whereas these findings were much diminished in A(3)-deficient mice and were not different from those in PBS-treated controls. These data indicate that the airway responses to aerosolized adenosine in mice occur largely through A(3) receptor activation and that mast cells contribute significantly to these responses, but that activation of additional adenosine receptors on a cell type(s) other than mast cells also contributes to adenosine-induced airway responsiveness in mice. Finally, our findings indicate that adenosine exposure can result in A(3)-dependent airway inflammation, as reflected in neutrophil recruitment, as well as alterations in airway function.
View details for Web of Science ID 000183674400042
View details for PubMedID 12817015
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Highly or poorly cytokinergic IgE molecules mediate a spectrum of effects on mast cell survival and activation
90th Annual Meeting of the American-Association-for-Immunologists
FEDERATION AMER SOC EXP BIOL. 2003: C11–C11
View details for Web of Science ID 000182367000053
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Severe anaphylactic reactions to glutamic acid decarboxylase (GAD) self peptides in NOD mice that spontaneously develop autoimmune type 1 diabetes mellitus.
BMC immunology
2003; 4: 2-?
Abstract
Insulin dependent (i.e., "type 1") diabetes mellitus (T1DM) is considered to be a T cell mediated disease in which TH1 and Tc autoreactive cells attack the pancreatic islets. Among the beta-cell antigens implicated in T1DM, glutamic acid decarboxylase (GAD) 65 appears to play a key role in the development of T1DM in humans as well as in non-obese diabetic (NOD) mice, the experimental model for this disease. It has been shown that shifting the immune response to this antigen from TH1 towards TH2, via the administration of GAD65 peptides to young NOD mice, can suppress the progression to overt T1DM. Accordingly, various protocols of "peptide immunotherapy" of T1DM are under investigation. However, in mice with experimental autoimmune encephalomyelitis (EAE), another autoimmune TH1 mediated disease that mimics human multiple sclerosis, anaphylactic shock can occur when the mice are challenged with certain myelin self peptides that initially were administered with adjuvant to induce the disease.Here we show that NOD mice, that spontaneously develop T1DM, can develop fatal anaphylactic reactions upon challenge with preparations of immunodominant GAD65 self peptides after immunization with these peptides to modify the development of T1DM.These findings document severe anaphylaxis to self peptide preparations used in an attempt to devise immunotherapy for a spontaneous autoimmune disease. Taken together with the findings in EAE, these results suggest that peptide therapies designed to induce a TH1 to TH2 shift carry a risk for the development of anaphylactic reactivity to the therapeutic peptides.
View details for PubMedID 12597780
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Multiple elements of the allergic arm of the immune response modulate autoimmune demyelination
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2003; 100 (4): 1867-1872
Abstract
Analysis of mRNA from multiple sclerosis lesions revealed increased amounts of transcripts for several genes encoding molecules traditionally associated with allergic responses, including prostaglandin D synthase, histamine receptor type 1 (H1R), platelet activating factor receptor, Ig Fc epsilon receptor 1 (Fc epsilon RI), and tryptase. We now demonstrate that, in the animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), mediated by T helper 1 (Th1) T cells, histamine receptor 1 and 2 (H1R and H2R) are present on inflammatory cells in brain lesions. Th1 cells reactive to myelin proteolipid protein expressed more H1R and less H2R than Th2 cells. Pyrilamine, an H1R antagonist, blocked EAE, and the platelet activating factor receptor antagonist CV6209 reduced the severity of EAE. EAE severity was also decreased in mice with disruption of the genes encoding Ig Fc gamma RIII or both Fc gamma RIII and Fc epsilon RI. Prostaglandin D synthase and tryptase transcripts were elevated in EAE brain. Taken together, these data reveal extensive involvement of elements of the immune response associated with allergy in autoimmune demyelination. The pathogenesis of demyelination must now be viewed as encompassing elements of both Th1 responses and "allergic" responses.
View details for DOI 10.1073/pnas.252777399
View details for Web of Science ID 000181073000077
View details for PubMedID 12576552
View details for PubMedCentralID PMC149925
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Regulation of mast-cell and basophil function and survival by IgE
NATURE REVIEWS IMMUNOLOGY
2002; 2 (10): 773-786
Abstract
Mast cells and basophils are important effector cells in T helper 2 (T(H)2)-cell-dependent, immunoglobulin-E-associated allergic disorders and immune responses to parasites. The crosslinking of IgE that is bound to the high-affinity receptor Fc epsilon RI with multivalent antigen results in the aggregation of Fc epsilon RI and the secretion of products that can have effector, immunoregulatory or autocrine effects. This response can be enhanced markedly in cells that have been exposed to high levels of IgE, which results in the increased surface expression of Fc epsilon RI. Moreover, recent work indicates that monomeric IgE (in the absence of crosslinking) can render mast cells resistant to apoptosis induced by growth-factor deprivation in vitro and, under certain circumstances, can induce the release of cytokines. So, the binding of IgE to Fc epsilon RI might influence mast-cell and basophil survival directly or indirectly, and can also regulate cellular function.
View details for DOI 10.1038/nri914
View details for Web of Science ID 000180439500021
View details for PubMedID 12360215
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Probing the roles of mast cells and basophils in natural and acquired immunity, physiology and disease.
Trends in immunology
2002; 23 (9): 425-427
View details for PubMedID 12200056
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Transcriptional response of human mast cells stimulated via the Fc(epsilon)RI and identification of mast cells as a source of IL-11.
BMC immunology
2002; 3: 5-?
Abstract
In asthma and other allergic disorders, the activation of mast cells by IgE and antigen induces the cells to release histamine and other mediators of inflammation, as well as to produce certain cytokines and chemokines. To search for new mast cell products, we used complementary DNA microarrays to analyze gene expression in human umbilical cord blood-derived mast cells stimulated via the high-affinity IgE receptor (Fc(epsilon)RI).One to two hours after Fc(epsilon)RI-dependent stimulation, more than 2,400 genes (about half of which are of unknown function) exhibited 2-200 fold changes in expression. The transcriptional program included changes in the expression of IL-11 and at least 30 other cytokines and chemokines. Human mast cells secreted 130-529 pg of IL-11/106 cells by 6 h after stimulation with anti-IgE.Our initial analysis of the transcriptional program induced in in vitro-derived human mast cells stimulated via the Fc(epsilon)RI has identified many products that heretofore have not been associated with this cell type, but which may significantly influence mast cell function in IgE-associated host responses. We also have demonstrated that mast cells stimulated via the Fc(epsilon)RI can secrete IL-11. Based on the previously reported biological effects of IL-11, our results suggest that production of IL-11 may represent one link between IgE-dependent mast cell activation in subjects with allergic asthma and the development of a spectrum of structural changes in the airways of these individuals; such changes, collectively termed "airway remodeling," can constitute an important long term consequence of asthma.
View details for PubMedID 12079505
View details for PubMedCentralID PMC116674
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Gene-microarray analysis of multiple sclerosis lesions yields new targets validated in autoimmune encephalomyelitis
NATURE MEDICINE
2002; 8 (5): 500-508
Abstract
Microarray analysis of multiple sclerosis (MS) lesions obtained at autopsy revealed increased transcripts of genes encoding inflammatory cytokines, particularly interleukin-6 and -17, interferon-gamma and associated downstream pathways. Comparison of two poles of MS pathology--acute lesions with inflammation versus 'silent' lesions without inflammation--revealed differentially transcribed genes. Some products of these genes were chosen as targets for therapy of experimental autoimmune encephalomyelitis (EAE) in mice. Granulocyte colony-stimulating factor is upregulated in acute, but not in chronic, MS lesions, and the effect on ameliorating EAE is more pronounced in the acute phase, in contrast to knocking out the immunoglobulin Fc receptor common gamma chain where the effect is greatest on chronic disease. These results in EAE corroborate the microarray studies on MS lesions. Large-scale analysis of transcripts in MS lesions elucidates new aspects of pathology and opens possibilities for therapy.
View details for DOI 10.1038/nm0502-500
View details for PubMedID 11984595
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Regulation of mast cell survival by IgE
IMMUNITY
2001; 14 (6): 791-800
Abstract
Mast cells play critical roles in hypersensitivity and in defense against certain parasites. We provide evidence that mouse mast cell survival and growth are promoted by monomeric IgE binding to its high-affinity receptor, Fc epsilon RI. Monomeric IgE does not promote DNA synthesis but suppresses the apoptosis induced by growth factor deprivation. This antiapoptotic effect occurs in parallel with IgE-induced increases in Fc epsilon RI surface expression but requires the continuous presence of IgE. This process does not involve the FasL/Fas death pathway or several Bcl-2 family proteins and induces a distinctly different signal than Fc epsilon RI cross-linking. The ability of IgE to enhance mast cell survival and Fc epsilon RI expression may contribute to amplified allergic reactions.
View details for Web of Science ID 000169495100014
View details for PubMedID 11420048
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Allergy to self: An unexpected immune response in EAE
LIPPINCOTT WILLIAMS & WILKINS. 2001: A94
View details for Web of Science ID 000168270600246
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The transcriptional program in human mast cells stimulated via the Fc[epsilon]RI: New insights into the immunological functions of mast cells in allergic inflammation.epsilon
FEDERATION AMER SOC EXP BIOL. 2001: A1020–A1020
View details for Web of Science ID 000167454201772
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An unexpected version of horror autotoxicus. Anaphylactic shock to a self peptide.
FEDERATION AMER SOC EXP BIOL. 2001: A1218–A1218
View details for Web of Science ID 000167454202911
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An unexpected version of horror autotoxicus: anaphylactic shock to a self peptide
NATURE IMMUNOLOGY
2001; 2 (3): 216-222
Abstract
EAE can refer either to experimental autoimmune encephalomyelitis or experimental allergic encephalomyelitis. Although EAE is classically a prototypic T helper 1 (TH1) cell-mediated autoimmune disease, it can also be induced by TH2 cells. Characteristically, the most severe manifestation of allergy, anaphylaxis, is associated with exposure to a foreign antigen that is often derived from medication, insect venom or food. We report here that, after self-tolerance to myelin is destroyed, anaphylaxis may be triggered by a self-antigen, in this case a myelin peptide. "Horror autotoxicus", which was initially described by Ehrlich, may not only include autoimmunity to self, it may also encompass immediate hypersensitivity to self, which leads to shock and rapid death.
View details for Web of Science ID 000167413800013
View details for PubMedID 11224520
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IgE promotes contact hypersensitivity responses in mice
MOSBY-ELSEVIER. 2001: S322-S323
View details for Web of Science ID 000167172301047
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Mast cells can amplify airway reactivity and features of chronic inflammation in an asthma model in mice
JOURNAL OF EXPERIMENTAL MEDICINE
2000; 192 (3): 455-462
Abstract
The importance of mast cells in the development of the allergen-induced airway hyperreactivity and inflammation associated with asthma remains controversial. We found that genetically mast cell-deficient WBB6F(1)-W/W(v) mice that were sensitized to ovalbumin (OVA) without adjuvant, then challenged repetitively with antigen intranasally, exhibited much weaker responses in terms of bronchial hyperreactivity to aerosolized methacholine, lung tissue eosinophil infiltration, and numbers of proliferating cells within the airway epithelium than did identically treated WBB6F(1)-+/+ normal mice. However, W/W(v) mice that had undergone selective reconstitution of tissue mast cells with in vitro-derived mast cells of congenic +/+ mouse origin exhibited airway responses that were very similar to those of the +/+ mice. By contrast, W/W(v) mice that were sensitized with OVA emulsified in alum and challenged with aerosolized OVA exhibited levels of airway hyperreactivity and lung tissue eosinophil infiltration that were similar to those of the corresponding +/+ mice. Nevertheless, these W/W(v) mice exhibited significantly fewer proliferating cells within the airway epithelium than did identically treated +/+ mice. These results show that, depending on the "asthma model" investigated, mast cells can either have a critical role in, or not be essential for, multiple features of allergic airway responses in mice.
View details for Web of Science ID 000088708800016
View details for PubMedID 10934234
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In vivo immunological function of mast cells derived from embryonic stem cells: An approach for the rapid analysis of even embryonic lethal mutations in adult mice in vivo
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2000; 97 (16): 9186-9190
Abstract
An important goal of tissue engineering is to achieve reconstitution of specific functionally active cell types by transplantation of differentiated cell populations derived from normal or genetically altered embryonic stem cells in vitro. We find that mast cells derived in vitro from wild-type or genetically manipulated embryonic stem cells can survive and orchestrate immunologically specific IgE-dependent reactions after transplantation into mast cell-deficient Kit(W)/Kit(W-v) mice. These findings define a unique approach for analyzing the effects of mutations of any genes that are expressed in mast cells, including embryonic lethal mutations, in vitro or in vivo.
View details for Web of Science ID 000088608000077
View details for PubMedID 10908668
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A role for Bax in the regulation of apoptosis in mouse mast cells
JOURNAL OF INVESTIGATIVE DERMATOLOGY
2000; 114 (6): 1205-1206
View details for Web of Science ID 000087365800022
View details for PubMedID 10844568
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The diverse potential effector and immunoregulatory roles of mast cells in allergic disease
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2000; 105 (5): 847-859
Abstract
Mast cells are of hematopoietic origin but typically complete their maturation in peripheral connective tissues, especially those near epithelial surfaces. Mast cells express receptors that bind IgE antibodies with high affinity (FcepsilonRI), and aggregation of these FcepsilonRI by the reaction of cell-bound IgE with specific antigens induces mast cells to secrete a broad spectrum of biologically active preformed or lipid mediators, as well as many cytokines. Mast cells are widely thought to be essential for the expression of acute allergic reactions, but the importance of mast cells in late-phase reactions and chronic allergic inflammation has remained controversial. Although it is clear that many cell types may be involved in the expression of late-phase reactions and chronic allergic inflammation, studies in genetically mast cell-deficient and congenic normal mice indicate that mast cells may be critical for the full expression of certain features of late-phase reactions and may also contribute importantly to clinically relevant aspects of chronic allergic inflammation. Moreover, the pattern of cytokines that can be produced by mast cell populations, and the enhancement of such cytokine production in mast cells that have undergone IgE-dependent up-regulation of their surface expression of FcepsilonRI, suggests that mast cells may contribute to allergic diseases (and host defense) by acting as immunoregulatory cells, as well as by providing effector cell function.
View details for Web of Science ID 000087185000001
View details for PubMedID 10808163
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Phenotype and in vivo function of mast cells derived from mouse embryonic stem cells.
FEDERATION AMER SOC EXP BIOL. 2000: A1128–A1128
View details for Web of Science ID 000086643101273
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Mast cells and basophils
CURRENT OPINION IN HEMATOLOGY
2000; 7 (1): 32-39
Abstract
Mast cells and basophils are effector cells in IgE-associated immune responses, such as those that contribute to asthma and other allergic diseases and to host resistance to parasites. Recent work shows that mast cells can also participate in innate immunity to bacterial infection and that the expression of such mast cell-dependent natural immunity can be significantly enhanced by long-term treatment of mice with the kit ligand, stem cell factor. However, mast cells may also influence many other biologic responses, including tissue remodeling and angiogenesis. This review discusses certain recent findings about the differentiation, phenotype, and function of basophils and mast cells, as well as briefly considering evolving concepts about the roles of these cells in health and disease.
View details for Web of Science ID 000165671100007
View details for PubMedID 10608502
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Dexamethasone decreases the levels of surface Fc epsilon RI expression in mouse mast cells
MOSBY-YEAR BOOK INC. 2000: S62
View details for DOI 10.1016/S0091-6749(00)90619-5
View details for Web of Science ID 000085530100187
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Mast-cell heparin demystified.
Nature
1999; 400 (6746): 714-715
View details for PubMedID 10466718
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IgE enhances Fc epsilon receptor I expression and IgE-dependent release of histamine and lipid mediators from human umbilical cord blood-derived mast cells: Synergistic effect of IL-4 and IgE on human mast cell Fc epsilon receptor I expression and mediator release
JOURNAL OF IMMUNOLOGY
1999; 162 (9): 5455-5465
Abstract
We investigated the effects of IgE versus IL-4 on Fc epsilon RI surface expression in differentiated human mast cells derived in vitro from umbilical cord blood mononuclear cells. We found that IgE (at 5 micrograms/ml) much more strikingly enhanced surface expression of Fc epsilon RI than did IL-4 (at 0.1-100 ng/ml); similar results were also obtained with differentiated mouse mast cells. However, IL-4 acted synergistically with IgE to enhance Fc epsilon RI expression in these umbilical cord blood-derived human mast cells, as well as in mouse peritoneal mast cells derived from IL-4-/- or IL-4+/+ mice. We also found that: 1) IgE-dependent enhancement of Fc epsilon RI expression was associated with a significantly enhanced ability of these human mast cells to secrete histamine, PGD2, and leukotriene C4 upon subsequent passive sensitization with IgE and challenge with anti-IgE; 2) preincubation with IL-4 enhanced IgE-dependent mediator secretion in these cells even in the absence of significant effects on Fc epsilon RI surface expression; 3) when used together with IgE, IL-4 enhanced IgE-dependent mediator secretion in human mast cells to levels greater than those observed in cells that had been preincubated with IgE alone; and 4) batches of human mast cells generated in vitro from umbilical cord blood cells derived from different donors exhibited differences in the magnitude and pattern of histamine and lipid mediator release in response to anti-IgE challenge, both under baseline conditions and after preincubation with IgE and/or IL-4.
View details for Web of Science ID 000079892600059
View details for PubMedID 10228025
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Spontaneous canine mast cell tumors express tandem duplications in the proto-oncogene c-kit
EXPERIMENTAL HEMATOLOGY
1999; 27 (4): 689-697
Abstract
Spontaneous mast cell tumors (MCT) are the most common malignant neoplasm in the dog, representing between 7% and 21% of all canine tumors, an incidence much higher than that found in humans. These tumors often behave in an aggressive manner, metastasizing to local lymph nodes, liver, spleen, and bone marrow. The proto-oncogene c-kit is known to play a critical role in the development and function of mast cells. Point mutations in the kinase domain of c-kit leading to tyrosine phosphorylation in the absence of ligand binding have been identified in three mastocytoma lines, (P815, RBL, and HMC-1), and some human patients with various forms of mastocytosis. We now demonstrate that although c-kit derived from canine MCT did not contain the previously described activating point mutations, 5 of the 11 tumors analyzed possessed novel mutations consisting of tandem duplications involving exons 11 and 12. We also show that one such duplication, detected in a canine mastocytoma cell line, was associated with constitutive phosphorylation of c-kit protein (KIT), suggesting that these mutations may contribute to the development or progression of canine MCT.
View details for Web of Science ID 000079690600013
View details for PubMedID 10210327
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Mast cells as sentinels of innate immunity
CURRENT OPINION IN IMMUNOLOGY
1999; 11 (1): 53-59
Abstract
Mast cells are widely regarded as important effector cells in immune responses associated with Th2 cells and IgE. Recent work shows that they can also contribute significantly to the expression of innate immunity; furthermore, survival in a model of acute bacterial infection that is dependent on complement and mast cells can be greatly enhanced by long-term treatment of mice with the kit ligand (stem cell factor) at least in part because of the effects of such treatment on mast cell numbers and/or function. These findings not only indicate that mast cells can represent a critical component of host defense in natural immunity but also suggest that mast cell function in this setting can be manipulated for therapeutic ends.
View details for Web of Science ID 000078614200009
View details for PubMedID 10047539
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The c-kit ligand, stem cell factor, can enhance innate immunity through effects on mast cells
JOURNAL OF EXPERIMENTAL MEDICINE
1998; 188 (12): 2343-2348
Abstract
Mast cells are thought to contribute significantly to the pathology and mortality associated with anaphylaxis and other allergic disorders. However, studies using genetically mast cell-deficient WBB6F1-KitW/KitW-v and congenic wild-type (WBB6F1-+/+) mice indicate that mast cells can also promote health, by participating in natural immune responses to bacterial infection. We previously reported that repetitive administration of the c-kit ligand, stem cell factor (SCF), can increase mast cell numbers in normal mice in vivo. In vitro studies have indicated that SCF can also modulate mast cell effector function. We now report that treatment with SCF can significantly improve the survival of normal C57BL/6 mice in a model of acute bacterial peritonitis, cecal ligation and puncture (CLP). Experiments in mast cell-reconstituted WBB6F1-KitW/KitW-v mice indicate that this effect of SCF treatment reflects, at least in part, the actions of SCF on mast cells. Repetitive administration of SCF also can enhance survival in mice that genetically lack tumor necrosis factor (TNF)-alpha, demonstrating that the ability of SCF treatment to improve survival after CLP does not solely reflect effects of SCF on mast cell- dependent (or -independent) production of TNF-alpha. These findings identify c-kit and mast cells as potential therapeutic targets for enhancing innate immune responses.
View details for Web of Science ID 000077713600015
View details for PubMedID 9858520
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Mast cells can secrete vascular permeability factor vascular endothelial cell growth factor and exhibit enhanced release after immunoglobulin E-dependent upregulation of Fc epsilon receptor I expression
JOURNAL OF EXPERIMENTAL MEDICINE
1998; 188 (6): 1135-1145
Abstract
Vascular permeability factor/vascular endothelial cell growth factor (VPF/VEGF) can both potently enhance vascular permeability and induce proliferation of vascular endothelial cells. We report here that mouse or human mast cells can produce and secrete VPF/VEGF. Mouse mast cells release VPF/VEGF upon stimulation through Fcepsilon receptor I (FcepsilonRI) or c-kit, or after challenge with the protein kinase C activator, phorbol myristate acetate, or the calcium ionophore, A23187; such mast cells can rapidly release VPF/VEGF, apparently from a preformed pool, and can then sustain release by secreting newly synthesized protein. Notably, the Fc epsilonRI-dependent secretion of VPF/VEGF by either mouse or human mast cells can be significantly increased in cells which have undergone upregulation of Fc epsilonRI surface expression by a 4-d preincubation with immunoglobulin E. These findings establish that at least one cell type, the mast cell, can be stimulated to secrete VPF/VEGF upon immunologically specific activation via a member of the multichain immune recognition receptor family. Our observations also identify a new mechanism by which mast cells can contribute to enhanced vascular permeability and/or angiogenesis, in both allergic diseases and other settings.
View details for Web of Science ID 000076112700014
View details for PubMedID 9743532
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Involvement of Bruton's tyrosine kinase in Fc epsilon RI-dependent mast cell degranulation and cytokine production
JOURNAL OF EXPERIMENTAL MEDICINE
1998; 187 (8): 1235-1247
Abstract
We investigated the role of Bruton's tyrosine kinase (Btk) in FcepsilonRI-dependent activation of mouse mast cells, using xid and btk null mutant mice. Unlike B cell development, mast cell development is apparently normal in these btk mutant mice. However, mast cells derived from these mice exhibited significant abnormalities in FcepsilonRI-dependent function. xid mice primed with anti-dinitrophenyl monoclonal IgE antibody exhibited mildly diminished early-phase and severely blunted late-phase anaphylactic reactions in response to antigen challenge in vivo. Consistent with this finding, cultured mast cells derived from the bone marrow cells of xid or btk null mice exhibited mild impairments in degranulation, and more profound defects in the production of several cytokines, upon FcepsilonRI cross-linking. Moreover, the transcriptional activities of these cytokine genes were severely reduced in FcepsilonRI-stimulated btk mutant mast cells. The specificity of these effects of btk mutations was confirmed by the improvement in the ability of btk mutant mast cells to degranulate and to secrete cytokines after the retroviral transfer of wild-type btk cDNA, but not of vector or kinase-dead btk cDNA. Retroviral transfer of Emt (= Itk/Tsk), Btk's closest relative, also partially improved the ability of btk mutant mast cells to secrete mediators. Taken together, these results demonstrate an important role for Btk in the full expression of FcepsilonRI signal transduction in mast cells.
View details for Web of Science ID 000073287900008
View details for PubMedID 9547335
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P- and E-selectins are required for the leukocyte recruitment, but not the tissue swelling, associated with IgE- and mast cell-dependent inflammation in mouse skin
LABORATORY INVESTIGATION
1998; 78 (4): 497-505
Abstract
Many studies, in both experimental animal and human systems, have indicated that P- and/or E-selectins may contribute importantly to the leukocyte recruitment that occurs in association with mast cell-dependent inflammatory responses. We used mice that genetically lack P-selectin (P -/-), E-selectin (E -/-), or both selectins (P/E -/-) to investigate the possible roles of these selectins in the IgE- and mast cell-dependent recruitment of neutrophils to the skin of mice. We found that a lack of either or both selectins had little or no effect on the extent of mast cell degranulation or the tissue swelling associated with these reactions. Moreover, a lack of either P- or E-selectin alone did not reduce the neutrophil infiltration at the reaction sites. However, mice lacking both P- and E-selectins exhibited an almost complete ablation of IgE- and mast cell-dependent neutrophil recruitment. These findings show that P- and E-selectins can express overlapping functions in leukocyte recruitment associated with IgE- and mast cell-dependent cutaneous late-phase reactions in mouse skin, and that a lack of both selectins results in a virtual elimination of IgE-dependent leukocyte recruitment.
View details for Web of Science ID 000073169200013
View details for PubMedID 9564894
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Role for interleukin-3 in mast-cell and basophil development and in immunity to parasites
NATURE
1998; 392 (6671): 90-93
Abstract
The cytokine interleukin-3 (IL-3), which can be derived from T cells and other sources, is a potentially important link between the immune and haematopoietic systems. IL-3 may be particularly critical for the development, survival and function of tissue mast cells and blood basophils, which are thought to be important effector cells in immunity to parasites and other immunological responses, such as allergic reactions. Here we show, using IL-3-deficient mice, that IL-3 is not essential for the generation of mast cells or basophils under physiological conditions, but that it does contribute to increased numbers of tissue mast cells, enhanced basophil production, and immunity in mice infected with the nematode Stronglyoides venezuelensis. Parasite expulsion and mast-cell development are impaired even more severely in IL-3-deficient mice that also show a marked reduction in signalling by c-kit. These findings establish a role for IL-3 in immunity to parasites and indicate that one of the functions of IL-3 in host defence against infection is to expand populations of haematopoietic effector cells.
View details for Web of Science ID 000072373000056
View details for PubMedID 9510253
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Involvement of interleukin-3 in delayed-type hypersensitivity
BLOOD
1998; 91 (3): 778-783
Abstract
The in vivo functions of interleukin-3 (IL-3) were investigated by generating IL-3-deficient mice. Although hematopoiesis was unimpaired in homozygous mutant animals, contact hypersensitivity reactions were compromised. IL-3 was required for efficient priming of hapten-specific contact hypersensitivity responses, but was dispensable for T-cell-dependent sensitization to tumor cells. These findings reveal a critical role for IL-3 in some forms of delayed-type hypersensitivity.
View details for Web of Science ID 000071644000007
View details for PubMedID 9446636
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Impaired mast cell-dependent natural immunity in complement C3-deficient mice
NATURE
1997; 390 (6656): 172-175
Abstract
The complement system is widely regarded as essential for normal inflammation, not least because of its ability to activate mast cells. However, recent studies have called into question the importance of complement in several examples of mast cell-dependent inflammatory responses. To investigate the role of complement in mast cell-dependent natural immunity, we examined the responses of complement-deficient mice to caecal ligation and puncture, a model of acute septic peritonitis that is dependent on mast cells and tumour necrosis factor-alpha (TNF-alpha). We found that C4- or C3-deficient mice were much more sensitive to caecal ligation and puncture than wild-type (WT) controls (100% versus 20% in 24-h mortality, respectively). C3-deficient mice also exhibited reductions in peritoneal mast cell degranulation, production of TNF-alpha, neutrophil infiltration and clearance of bacteria. Treating the C3-deficient mice with purified C3 protein enhanced activation of peritoneal mast cells, TNF-alpha production, neutrophil recruitment, opsonophagocytosis of bacteria and resistance to caecal ligation and puncture, confirming that the defects were complement-dependent. These results provide formal evidence that complement activation is essential for the full expression of innate immunity in this mast cell-dependent model of bacterial infection.
View details for Web of Science ID A1997YF49400054
View details for PubMedID 9367154
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Expression of functional TrkA receptor tyrosine kinase in the HMC-1 human mast cell line and in human mast cells
BLOOD
1997; 90 (5): 1807-1820
Abstract
Nerve growth factor (NGF) can influence mast cell development and function in murine rodents by interacting with its receptors on mast cells. We now report the identification of mRNA transcripts of full-length tyrosine kinase-containing trkA, trkB, and trkC neurotrophin receptor genes in HMC-1 human mast cell leukemia cells. Although HMC-1 cells lacked p75 mRNA, they expressed transcripts for the exon-lacking splice variant of trkA (trkAI), truncated trkB (trkB.T1), and truncated trkC. By flow cytometry, HMC-1 cells exhibited expression of TrkA, TrkB, and TrkC receptor proteins containing full-length tyrosine kinase domains. NGF stimulation of HMC-1 cells induced tyrosine phosphorylation of TrkA protein, increased expression of the early response genes c-fos and NGF1-A, and activation of ERK-mitogen-activated protein (MAP) kinase, results which indicate that TrkA receptors in HMC-1 cells are fully functional. Highly purified populations of human lung mast cells expressed mRNAs for trkA, trkB and trkC, whereas preparations of human umbilical cord blood-derived mast cells expressed mRNAs for trkA and trkC, but not trkB. Moreover, preparations of human umbilical cord blood-derived immature mast cells not only expressed mRNA transcript and protein for TrkA, but exhibited significantly higher numbers of chymase-positive cells after the addition of NGF to their culture medium for 3 weeks. In addition, HMC-1 cells expressed mRNAs for NGF, brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), the cognate ligands for TrkA, TrkB, and TrkC, whereas NGF and BDNF transcripts were detectable in human umbilical cord blood mast cell preparations. Taken together, our findings show that human mast cells express a functional TrkA receptor tyrosine kinase and indicate that NGF may be able to promote certain aspects of mast cell development and/or maturation in humans. Our studies also raise the possibility that human mast cells may represent a potential source for neurotrophins.
View details for Web of Science ID A1997XX16600009
View details for PubMedID 9292513
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Complexity and redundancy in the pathogenesis of asthma: Reassessing the roles of mast cells and T cells
JOURNAL OF EXPERIMENTAL MEDICINE
1997; 186 (3): 343-347
View details for Web of Science ID A1997XP99800001
View details for PubMedID 9265074
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The Paul Kallos Memorial Lecture. The mast cell: a versatile effector cell for a challenging world.
International archives of allergy and immunology
1997; 113 (1-3): 14-22
Abstract
Mast cells are phenotypically and functionally versatile effector cells. When activated by IgE-dependent or other mechanisms, mast cells can produce a diverse array of mediators including TNF-alpha and many other cytokines. Moreover, mast cells can express increased numbers of high-affinity surface receptors for IgE (Fc epsilonRI) and enhanced levels of IgE-dependent mediator secretion in response to elevations in concentrations of IgE. These characteristics (and others) have suggested diverse potential roles for mast cells in health and disease. To test specific hypotheses about mast cell function in allergic reactions and other biological responses in vivo, one can employ genetically mast-cell-deficient Kit(W)/Kit(W-v) mice which do or do not contain adoptively transferred mast cell populations derived from genetically compatible wild-type mice or mice with mutations that influence mast cell biology. Such work has already indicated that mast cells (and, in some cases, mast-cell-derived cytokines) can have a critical role in the expression of the acute, late-phase and chronic components of IgE-dependent allergic inflammation and can influence the development of an important functional consequence of such reactions: airways hyperresponsiveness. However, mast cells can also perform important beneficial roles in host defense, both in IgE-dependent immune responses to certain parasites and in natural immunity to bacterial infection.
View details for PubMedID 9130474
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Differential release of mast cell interleukin-6 via c-kit
BLOOD
1997; 89 (8): 2654-2663
Abstract
Mast cells represent a potential source of interleukin-6 (IL-6) and other cytokines that have been implicated in host defense, tissue maintenance/remodeling, immunoregulation, and many other biologic responses. In acquired immune responses to parasites or allergens, the extensive IgE-dependent activation of mast cells via Fc epsilonRI can result in the release of large quantities of biogenic amines that are stored in the cells' cytoplasmic granules as well as the production of lipid mediators and many cytokines; these products together can orchestrate an intense inflammatory response. We now report that activation of mouse mast cells via c-kit, the receptor for the pleiotropic survival/growth factor, stem cell factor (SCF), can induce the release of IL-6. Upon challenge with SCF, bone marrow-derived cultured mouse mast cells (BMCMCs) released amounts of IL-6 that were greater than 100-fold more than those produced by unstimulated cells, but that were substantially less than those produced in response to IgE and specific antigen. Moreover, BMCMCs released IL-6 upon challenge with concentrations of SCF that resulted in little or no detectable release of tumor necrosis factor-alpha, leukotriene C4, histamine, or serotonin. These findings indicate that SCF, a widely expressed protein that is critical for mast cell development and survival, can also regulate the differential release of mast cell mediators.
View details for Web of Science ID A1997WV14600004
View details for PubMedID 9108382
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IgE regulates mouse basophil Fc epsilon RI expression in vivo
JOURNAL OF IMMUNOLOGY
1997; 158 (6): 2517-2521
Abstract
The binding of IgE to high-affinity IgE receptors (Fc epsilon RI) on the surface of mast cells and basophils primes these cells to secrete a panel of proinflammatory mediators upon subsequent exposure to specific Ag. We now find that the level of Fc epsilon RI expression on bone marrow basophils in mice infected with the nematode Strongyloides venezuelensis exhibits a strong positive correlation with the serum concentration of IgE, as was previously reported for human blood basophils. Moreover, the administration of IgE in vivo can significantly upregulate Fc epsilon RI expression on mouse basophils, and genetically IgE-deficient (IgE -/-) mice exhibit a dramatic (approximately 81%) reduction of basophil Fc epsilon RI expression compared with the corresponding normal (IgE +/+) mice. The finding that IgE can be a major regulator of mouse basophil Fc epsilon RI expression in vivo identifies a potentially important mechanism for enhancing the expression of effector cell function in IgE-dependent allergic reactions or immunologic responses to parasites.
View details for Web of Science ID A1997WM43500003
View details for PubMedID 9058781
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Absence of Fc(epsilon)RI alpha chain results in upregulation of Fc gamma RIII-dependent mast cell degranulation and anaphylaxis - Evidence of competition between Fc(epsilon)RI and Fc gamma RIII for limiting amounts of FcR beta and gamma chains
JOURNAL OF CLINICAL INVESTIGATION
1997; 99 (5): 915-925
Abstract
In mouse mast cells, both Fc epsilonRI and Fc gammaRIII are alpha beta gamma2 tetrameric complexes in which different alpha chains confer IgE or IgG ligand recognition while the signaling FcR beta and gamma chains are identical. We used primarily noninvasive techniques (changes in body temperature, dye extravasation) to assess systemic anaphylactic responses in nonanesthetized wild-type, Fc epsilonRI alpha chain -/- and FcR gamma chain -/- mice. We confirm that systemic anaphylaxis in mice can be mediated largely through IgG1 and Fc gammaRIII and we provide direct evidence that these responses reflect activation of Fc gammaRIII rather than Fc gammaRI. Furthermore, we show that Fc gammaRIII-dependent responses are more intense in normal than in congenic mast cell-deficient KitW/KitW-v mice, indicating that Fc gammaRIII responses have mast cell-dependent and -independent components. Finally, we demonstrate that the upregulation of cell surface expression of Fc gammaRIII seen in Fc epsilonRI alpha chain -/- mice corresponds to an increased association of Fc gammaRIII alpha chains with FcR beta and gamma chains and is associated with enhanced Fc gammaRIII-dependent mast cell degranulation and systemic anaphylactic responses. Therefore, the phenotype of the Fc epsilonRI alpha chain -/- mice suggests that expression of Fc epsilonRI and Fc gammaRIII is limited by availability of the FcR beta and gamma chains and that, in normal mice, changes in the expression of one receptor (Fc epsilonRI) may influence the expression of functional responses dependent on the other (Fc gammaRIII).
View details for Web of Science ID A1997WN15200015
View details for PubMedID 9062349
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Systemic anaphylaxis in the mouse can be mediated largely through IgG, and Fc gamma RIII - Assessment of the cardiopulmonary changes, mast cell degranulation, and death associated with active or IgE- or IgG(1)-dependent passive anaphylaxis
JOURNAL OF CLINICAL INVESTIGATION
1997; 99 (5): 901-914
Abstract
We attempted to elicit active anaphylaxis to ovalbumin, or passive IgE- or IgG1-dependent anaphylaxis, in mice lacking either the Fc epsilonRI alpha chain or the FcR gamma chain common to Fc epsilonRI and Fc gammaRI/III, or in mice lacking mast cells (KitW/ KitW-v mice), and compared the responses to those in the corresponding wild-type mice. We found that the FcR gamma chain is required for the death, as well as for most of the pathophysiological changes, associated with active anaphylaxis or IgE- or IgG1-dependent passive anaphylaxis. Moreover, some of the physiological changes associated with either active, or IgG1-dependent passive, anaphylactic responses were significantly greater in Fc epsilonRI alpha chain -/- mice than in the corresponding normal mice. Finally, while both KitW/KitW-v and congenic +/+ mice exhibited fatal active anaphylaxis, mast cell-deficient mice exhibited weaker physiological responses than the corresponding wild-type mice in both active and IgG1-dependent passive systemic anaphylaxis. Our findings strongly suggest that while IgE antibodies and Fc epsilonRI may influence the intensity and/or kinetics of some of the pathophysiological changes associated with active anaphylaxis in the mouse, the mortality associated with this response can be mediated largely by IgG1 antibodies and Fc gammaRIII.
View details for Web of Science ID A1997WN15200014
View details for PubMedID 9062348
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IgE enhances mouse mast cell Fc epsilon RI expression in vitro and in vivo: Evidence for a novel amplification mechanism in IgE-dependent reactions
JOURNAL OF EXPERIMENTAL MEDICINE
1997; 185 (4): 663-672
Abstract
The binding of immunoglobulin E (IgE) to high affinity IgE receptors (Fc(epsilon)RI) expressed on the surface of mast cells primes these cells to secrete, upon subsequent exposure to specific antigen, a panel of proinflammatory mediators, which includes cytokines that can also have immunoregulatory activities. This IgE- and antigen-specific mast cell activation and mediator production is thought to be critical to the pathogenesis of allergic disorders, such as anaphylaxis and asthma, and also contributes to host defense against parasites. We now report that exposure to IgE results in a striking (up to 32-fold) upregulation of surface expression of Fc(epsilon)RI on mouse mast cells in vitro or in vivo. Moreover, baseline levels of Fc(epsilon)RI expression on peritoneal mast cells from genetically IgE-deficient (IgE -/-) mice are dramatically reduced (by approximately 83%) compared with those on cells from the corresponding normal mice. In vitro studies indicate that the IgE-dependent upregulation of mouse mast cell Fc(epsilon)RI expression has two components: an early cycloheximide-insensitive phase, followed by a later and more sustained component that is highly sensitive to inhibition by cycloheximide. In turn, IgE-dependent upregulation of Fc(epsilon)RI expression significantly enhances the ability of mouse mast cells to release serotonin, interleukin-6 (IL-6), and IL-4 in response to challenge with IgE and specific antigen. The demonstration that IgE-dependent enhancement of mast cell Fc(epsilon)RI expression permits mast cells to respond to antigen challenge with increased production of proinflammatory and immunoregulatory mediators provides new insights into both the pathogenesis of allergic diseases and the regulation of protective host responses to parasites.
View details for Web of Science ID A1997WK03800008
View details for PubMedID 9034145
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Earthquakes: Slow down for safety
NATURE
1996; 383 (6595): 21-22
View details for Web of Science ID A1996VF29500027
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Genetic analysis reveals cell type-specific regulation of receptor tyrosine kinase c-Kit by the protein tyrosine phosphatase SHP1
JOURNAL OF EXPERIMENTAL MEDICINE
1996; 184 (3): 1111-1126
Abstract
Receptor protein tyrosine kinases (RTKs) transmit downstream signals via interactions with secondary signaling molecules containing SH2 domains. Although many SH2-phosphotyrosyl interactions have been defined in vitro, little is known about the physiological significance of specific RTK/SH2 interactions in vivo. Also, little is known about the mechanisms by which specific RTKs interact with and/or are regulated by specific protein tyrosine phosphatases (PTPs). To address such issue, we carried out a genetic analysis of the previously reported biochemical interaction between the RTK c-Kit, encoded at the W locus, and the SH2-containing non-transmembrane PTP SHP1, encoded at the motheaten (me) locus (1). Mice carrying a kinase-defective allele of c-Kit (Wv/+) were crossed with me/+ mice, which carry one effectively null allele of SHP1, and then backcrossed to generate all possible allelic combinations. Our results indicate strong intergenic complementation between these loci in hematopoietic progenitor cells. Compared to progenitors purified from normal mice, bone marrow progenitor cells (lin-) from me/me mice markedly hyper-proliferated in response to Kit ligand (KL). stimulation. Superimposition of the me/me genotype increased the number of one marrow-derived CFU-E from Wv/+ mice. Conversely, the presence of one or two copies of Wv decreased the number of macrophages and granulocytes in me/me lung, skin, peripheral blood and bone marrow, thereby decreasing the severity of the me/me phenotype. The decrease in dermal mast cells in Wv/Wv mice was rescued to levels found in Wv/+mice by superimposition of the me/me genotype. Surprisingly, however, the presence or absence of SHP1 had no effect on the proliferative response of bone marrow-derived cultured mast cells to KL or IL3 ex vivo. Nevertheless, the immediate-early response to KL stimulation, as measured by KL-induced tyrosyl phosphorylation, was substantially increased in mast cells from Wv/+:me/me compared to Wv/ +:+/+ mice, strongly suggesting that SHP1 directly dephosphorylates and regulates c-Kit. Taken together, our results establish that SHP1 negatively regulates signaling from c-Kit in vivo, but in a cell type-specific manner.
View details for Web of Science ID A1996VG86800032
View details for PubMedID 9064328
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Recombinant human stem cell factor (kit ligand) promotes human mast cell and melanocyte hyperplasia and functional activation in vivo
JOURNAL OF EXPERIMENTAL MEDICINE
1996; 183 (6): 2681-2686
Abstract
Stem cell factor (SCF), also known as mast cell growth factor, kit ligand, and steel factor, is the ligand for the tyrosine kinase receptor (SCFR) that is encoded by the c-kit proto-oncogene. We analyzed the effects of recombinant human SCF (r-hSCF, 5-50 micrograms/kg/day, injected subcutaneously) on mast cells and melanocytes in a phase I study of 10 patients with advanced breast carcinoma. A wheal and flare reaction developed at each r-hSCF injection site; by electron microscopy, most dermal mast cells at these sites exhibited extensive, anaphylactic-type degranulation. A 14-d course of r-hSCF significantly increased dermal mast cell density at sites distant to those injected with the cytokine and also increased both urinary levels of the major histamine metabolite, methyl-histamine, and serum levels of mast cell alpha-tryptase. Five subjects developed areas of persistent hyperpigmentation at r-hSCF injection sites; by light microscopy, these sites exhibited markedly increased epidermal melanization and increased numbers of melanocytes. The demonstration that r-hSCF can promote both the hyperplasia and the functional activation of human mast cells and melanocytes in vivo has implications for our understanding of the role of endogenous SCF in health and disease. These findings also indicate that the interaction between SCF and its receptor represents a potential therapeutic target for regulating the numbers and functional activity of both mast cells and cutaneous melanocytes.
View details for Web of Science ID A1996UT40100031
View details for PubMedID 8676090
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Identification of a committed precursor for the mast cell lineage
SCIENCE
1996; 271 (5250): 818-822
Abstract
Mast cells originate from hematopoietic stem cells, but the mast cell-committed precursor has not been identified. In the study presented here, a cell population in murine fetal blood that fulfills the criteria of progenitor mastocytes was identified. It is defined by the phenotype Thy-1loc-Kithi, contains cytoplasmic granules, and expresses RNAs encoding mast cell-associated proteases but lacks expression of the high-affinity immunoglobulin E receptor. Thy-1loc-Kithi cells generated functionally competent mast cells at high frequencies in vitro but lacked developmental potential for other hematopoietic lineages. When transferred intraperitoneally, this population reconstituted the peritoneal mast cell compartment of genetically mast cell-deficient W/Wv mice to wild-type levels.
View details for Web of Science ID A1996TU69400050
View details for PubMedID 8629001
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STEM-CELL FACTOR CONTRIBUTES TO INTESTINAL MUCOSAL MAST-CELL HYPERPLASIA IN RATS INFECTED WITH NIPPOSTRONGYLUS-BRASILIENSIS OR TRICHINELLA-SPIRALIS, BUT ANTI-STEM CELL FACTOR TREATMENT DECREASES PARASITE EGG-PRODUCTION DURING N-BRASILIENSIS INFECTION
BLOOD
1995; 86 (5): 1968-1976
Abstract
We assessed the effects of the c-kit ligand, stem cell factor (SCF), in the jejunal mucosal mast cell hyperplasia that occurs during infection with the intestinal nematodes, Nippostrongylus brasiliensis or Trichinella spiralis in rats. Compared with vehicle-treated rats, rats treated with SCF (25 micrograms/kg/d, intravenous [i.v.] for 14 days) during N brasiliensis infection exhibited significantly higher levels of the rat mucosal mast cell (MMC)-associated protease, rat mast cell protease II (RMCP II) in the jejunum and serum on day 8 of infection, but not on days 10 or 15 of infection. By contrast, in comparison to rats treated with normal sheep IgG, rats treated with a polyclonal sheep antirat SCF antibody exhibited markedly decreased numbers of jejunal MMCs, levels of jejunal RMCP II, and serum concentrations of RMCP II during infection with either nematode, particularly at the earlier intervals of infection (< or = day 10). Taken together, these findings indicate that SCF importantly contributes to MMC hyperplasia and/or survival during N brasiliensis or T spiralis infection in rats, but that levels of endogenous SCF are adequate to sustain near maximal MMC hyperplasia during infection with these nematodes. Notably, treatment of rats with SCF somewhat increased, and treatment with anti-SCF significantly decreased, parasite egg production during N brasiliensis infection. This finding raises the interesting possibility that certain activities of intestinal MMCs may contribute to parasite fecundity during infection with this nematode.
View details for Web of Science ID A1995RT38600039
View details for PubMedID 7544650
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DEXAMETHASONE OR CYCLOSPORINE-A SUPPRESS MAST CELL-LEUKOCYTE CYTOKINE CASCADES - MULTIPLE MECHANISMS OF INHIBITION OF IGE-DEPENDENT AND MAST-CELL-DEPENDENT CUTANEOUS INFLAMMATION IN THE MOUSE
JOURNAL OF IMMUNOLOGY
1995; 154 (3): 1391-1398
Abstract
In allergic diseases, exposure of sensitized subjects to allergen induces the activation of tissue mast cells that results in an immediate-type hypersensitivity response and, in some individuals, a a late phase response. We previously have reported that the neutrophil infiltration associated with IgE-dependent cutaneous inflammation in mice is mast cell-dependent and that TNF-alpha contributes significantly to this response. We report here that either dexamethasone or cyclosporin A can inhibit mouse mast cell TNF-alpha production in vitro, and that these agents also can significantly suppress the tissue swelling and leukocyte infiltration associated with two forms of TNF-alpha-associated inflammation in vivo: the entirely IgE- and mast cell-dependent inflammation at sites of passive cutaneous anaphylaxis reactions and the entirely TNF-alpha-dependent inflammation that is elicited by the direct intradermal injection of recombinant mouse TNF-alpha. Taken together, our in vitro and in vivo findings in mice indicate that dexamethasone or cyclosporin A can have at least three actions that interfere with the pathogenesis of IgE, mast cell, and cytokine-dependent inflammatory reactions:suppression of the IgE-dependent increase in TNF-alpha mRNA by mast cells, inhibition of the IgE-dependent production of TNF-alpha protein by mast cells, and diminution of the responsiveness of target cells to TNF-alpha. Our findings in mice raise the possibility that similar actions of these agents in humans may account for some of the clinical efficacy of corticosteroids and cyclosporin A in allergic diseases.
View details for Web of Science ID A1995QC54600045
View details for PubMedID 7822805
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The effects of stem cell factor, the ligand for the c-kit receptor, on mouse and human mast cell development, survival, and function
International Symposium on Biological and Molecular Aspects of Mast Cell and Basophil Differentiation and Function
RAVEN PRESS. 1995: 1–11
View details for Web of Science ID A1995BD27M00001
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Mast cell hyperplasia and activation in the context of helminth infection, a role for stem cell factor?
International Symposium on Biological and Molecular Aspects of Mast Cell and Basophil Differentiation and Function
RAVEN PRESS. 1995: 211–224
View details for Web of Science ID A1995BD27M00018
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PROMOTION OF MOUSE FIBROBLAST COLLAGEN GENE-EXPRESSION BY MAST-CELLS STIMULATED VIA THE FC(EPSILON)RI - ROLE FOR MAST CELL-DERIVED TRANSFORMING GROWTH-FACTOR-BETA AND TUMOR-NECROSIS-FACTOR-ALPHA
JOURNAL OF EXPERIMENTAL MEDICINE
1994; 180 (6): 2027-2037
Abstract
Chronic allergic diseases and other disorders associated with mast cell activation can also be associated with tissue fibrosis, but a direct link between mast cell mediator release and fibroblast collagen gene expression has not been established. Using in situ hybridization, we show that the elicitation of an IgE-dependent passive cutaneous anaphylaxis (PCA) reaction in mice results in a transient, but marked augmentation of steady state levels of type alpha-1 (I) collagen mRNA in the dermis. While peak levels of collagen mRNA expression in the skin are observed 16-24 h after mast cell activation, substantial numbers of dermal cells are strongly positive for collagen mRNA at 1 and 2 h after antigen challenge, before circulating inflammatory cells are recruited into the tissues. Furthermore, experiments in mast cell-reconstituted or genetically mast cell-deficient WBB6F1-W/Wv mice demonstrate that the increased expression of collagen mRNA at sites of PCA reactions is entirely mast cell dependent. In vitro studies show that the supernatants of mouse serosal mast cells activated via the Fc epsilon RI markedly increase type alpha-1 (I) collagen mRNA levels in mouse embryonic skin fibroblasts, and also upregulate collagen secretion by these cells. The ability of mast cell supernatants to induce increased steady state levels of collagen mRNA in mouse skin fibroblasts is markedly diminished by absorption with antibodies specific for either of two mast cell-derived cytokines, transforming growth factor beta (TGF-beta 1) or tumor necrosis factor alpha (TNF-alpha), and is eliminated entirely by absorption with antibodies against both cytokines. Taken together, these findings demonstrate that IgE-dependent mouse mast cell activation can induce a transient and marked increase in steady state levels of type alpha-1 (I) collagen mRNA in dermal fibroblasts and that mast cell-derived TGF-beta 1 and TNF-alpha importantly contribute to this effect.
View details for Web of Science ID A1994PU36100003
View details for PubMedID 7964480
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CYTOPLASMIC GRANULE FORMATION IN MOUSE PANCREATIC ACINAR-CELLS - EVIDENCE FOR FORMATION OF IMMATURE GRANULES (CONDENSING VACUOLES) BY AGGREGATION AND FUSION OF PROGRANULES OF UNIT SIZE, AND FOR REDUCTIONS IN MEMBRANE-SURFACE AREA AND IMMATURE GRANULE VOLUME DURING GRANULE MATURATION
CELL AND TISSUE RESEARCH
1994; 278 (2): 327-336
Abstract
We used a computer-assisted morphometry approach to analyze quantitatively the process of cytoplasmic granule formation in mouse pancreatic acinar cells stimulated with pilocarpine to induce secretion. Our findings suggest that each condensing vacuole/immature granule of pancreatic acinar cells is formed by the progressive aggregation of 106 to 128 "unit progranules" of narrowly fixed volume, define a range of 7.7 to 9.2 for the factor of volume condensation between the largest immature granules and the mature unit granule, and predict that the formation of a single mature unit granule by the aggregation and fusion of unit progranules involves a net reduction of at least 95% in the amount of membrane surface area associated with these structures.
View details for Web of Science ID A1994PM03400016
View details for PubMedID 8001087
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PIECEMEAL DEGRANULATION OF MAST-CELLS IN THE INFLAMMATORY EYELID LESIONS OF INTERLEUKIN-4 TRANSGENIC MICE - EVIDENCE OF MAST-CELL HISTAMINE-RELEASE IN-VIVO BY DIAMINE OXIDASE-GOLD ENZYME-AFFINITY ULTRASTRUCTURAL CYTOCHEMISTRY
BLOOD
1994; 83 (12): 3600-3612
Abstract
We used light and electron microscopy to analyze the eyelid inflammation that develops in transgenic mice that overexpress interleukin-4 (IL-4; Tepper et al, Cell 62:457, 1990). Analysis of alkaline Giemsa-stained plastic sections examined by light microscopy (Dvorak et al, J Exp Med 132:558, 1970), as well as by routine transmission electron microscopy, indicated that the mast cells in the inflammatory eyelid lesions were undergoing piecemeal degranulation, a form of secretion in which the cells' cytoplasmic granules exhibit characteristic morphologic changes that are thought to be associated with the prolonged, vesicle-mediated release of the granules' constituents. Moreover, by using a newly reported enzyme affinity-gold method, which stains histamine based on binding to diamine oxidase-gold (Dvorak et al, J Histochem Cytochem 41:787, 1993), we show that these activated mast cells had released much of their histamine content. The eyelid lesions also exhibited increased numbers of mast cells; interstitial fibrosis, particularly around cutaneous nerves and blood vessels; activated fibroblasts; focal axonal damage; venules with endothelial cells containing numerous vesiculo-vacuolar organelles; and infiltrates of neutrophils and eosinophils. Our findings illustrate that overexpression of the IL-4 gene in vivo can result in eyelid lesions associated with piecemeal degranulation of mast cells, as well as tissue fibrosis and a variety of other pathologic changes. These results also represent the first direct morphologic evidence for histamine secretion by mast cells in vivo.
View details for Web of Science ID A1994NR90500023
View details for PubMedID 7515717
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MAST-CELLS AUGMENT LESION SIZE AND PERSISTENCE DURING EXPERIMENTAL LEISHMANIA-MAJOR INFECTION IN THE MOUSE
JOURNAL OF IMMUNOLOGY
1994; 152 (9): 4563-4571
Abstract
Mast cells are a source of a variety of cytokines that may influence the host response to Leishmania major. To investigate the role of mast cells during L. major infection, we performed a morphometric analysis of mast cells at cutaneous sites in resistant C57BL/6 mice and susceptible BALB/c mice injected with L. major. Extensive dermal mast cell degranulation was found at sites of L. major infection in both strains of mice. We also examined the course of L. major infection in genetically mast cell-deficient WBB6F1-W/Wv or WCB6F1-Sl/Sld mice, their respective congenic normal (WBB6F1-(+/+) or WCB6F1-(+/+)) littermates, and WBB6F1-W/Wv mice that had been selectively and locally repaired of their cutaneous mast cell deficiency. We found that mast cells significantly augmented the intensity and maximal size of the cutaneous lesions at sites of L. major infection, and in some cases substantially prolonged the persistence of the reactions. However, the lesions ultimately resolved in both the mast cell-deficient and the congenic normal mice. In addition, the presence or absence of mast cells had little or no effect on the numbers of viable parasites recovered from the cutaneous lesions. Moreover, mast cell-deficient W/Wv mice and the congenic normal (+/+) mice produced similar levels of IFN-gamma mRNA in lymph nodes draining the cutaneous lesions whereas no IL-4 mRNA was detectable. Taken together, these data suggest that mast cells significantly augment the size of cutaneous lesions during L. major infection in mice. However, mast cells do not appear to influence significantly either the parasite burden or the ultimate resolution of the infection.
View details for Web of Science ID A1994NG71900036
View details for PubMedID 8157970
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IDENTIFICATION OF IGE-BEARING CELLS IN THE LATE-PHASE RESPONSE TO ANTIGEN IN THE LUNG AS BASOPHILS
AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY
1994; 10 (4): 384-390
Abstract
We have carried out studies to ascertain whether the histamine-containing, IgE-bearing cells found in the bronchoalveolar lavage (BAL) fluid obtained during the late-phase response following subsegmental antigen challenge of human airways are predominantly basophils or mast cells. Four lines of evidence suggest that most are basophils: (1) The cells fulfill morphologic criteria for light microscopy. (2) Cell surface markers determined by immunofluorescence and flow cytometry revealed that the IgE-bearing cells express the leukocyte antigens Fc gamma RII and the beta 2 integrins, LFA-1 and Mac-1, but do not express the mast cell-associated c-kit receptor for stem cell factor. (3) The late-phase histamine-containing cells in late-phase BAL fluids have the functional characteristics of basophils in their secretory responses to anti-IgE, the f-met peptide, and phorbol ester TPA. (4) The cells have a functional histamine type 2 receptor, a characteristic of basophils, not mast cells. We conclude that basophils infiltrate the lower airways hours after antigen exposure. These cells may be responsible for the mediator release observed at that time.
View details for Web of Science ID A1994NE36700006
View details for PubMedID 7510984
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THE KIT-LIGAND, STEM-CELL FACTOR
ADVANCES IN IMMUNOLOGY, VOL 55
1994; 55: 1-96
View details for Web of Science ID A1994BZ73F00001
View details for PubMedID 7508174
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EFFECTS OF INTERLEUKIN-3 WITH OR WITHOUT THE C-KIT LIGAND, STEM-CELL FACTOR, ON THE SURVIVAL AND CYTOPLASMIC GRANULE FORMATION OF MOUSE BASOPHILS AND MAST-CELLS IN-VITRO
AMERICAN JOURNAL OF PATHOLOGY
1994; 144 (1): 160-170
Abstract
We assessed the ultrastructure and the cell-surface expression of receptors for immunoglobulin E (Fc epsilon R), and c-kit, the receptor for stem cell factor (SCF), in mouse basophils and mast cells present in short-term cultures of mouse bone marrow cells in interleukin-3 (IL-3) with or without SCF. Basophils did not develop increased numbers of cytoplasmic granules and underwent apoptosis in cultures containing IL-3 and SCF, whereas mast cells thrived and developed increased numbers of granules. Basophils were nearly all Fc epsilon R+ c-kit- when sorted after culture in IL-3 and SCF; most mast cells were Fc epsilon R+ c-kit+. However, a second population of Fc epsilon R+ c-kit- mast cells was present after culture in IL-3 and SCF. These c-kit receptor-negative mast cells were less mature than c-kit+ mast cells and contained significantly fewer cytoplasmic granules than the c-kit+ mast cells present in the same cultures (P < 0.001). Thus, mouse basophils express little or no c-kit receptor on their surface, nor can they survive for long periods in SCF-supplemented cultures. By contrast, mouse mast cells seem to express the Fc epsilon R early in their development, even before they express detectable c-kit receptors on their surface. IL-3 promotes cytoplasmic granule formation in immature mast cells, but even more granules are formed when c-kit receptor-positive immature mast cells are cultured in both SCF and IL-3.
View details for Web of Science ID A1994MR31000017
View details for PubMedID 7507298
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EFFECTS OF CHRONIC TREATMENT WITH THE C-KIT LIGAND, STEM-CELL FACTOR, ON IMMUNOGLOBULIN-E DEPENDENT ANAPHYLAXIS IN MICE - GENETICALLY MAST-CELL DEFICIENT SL/SL(D) MICE ACQUIRE ANAPHYLACTIC RESPONSIVENESS, BUT THE CONGENIC NORMAL MICE DO NOT EXHIBIT AUGMENTED RESPONSES
JOURNAL OF CLINICAL INVESTIGATION
1993; 92 (4): 1639-1649
Abstract
We treated genetically mast cell-deficient WCB6F1-Sl/Sld mice and the congenic normal (WCB6F1(-)+/+) mice with the c-kit ligand recombinant rat stem cell factor164 (rrSCF164; 100 micrograms/kg per d, subcutaneously) or with vehicle for 21 d, then passively sensitized the mice with anti-dinitrophenol30-40 immunoglobulin E (IgE) antibodies, and 1 d later measured the changes in heart rate, pulmonary dynamic compliance, and pulmonary conductance, and assessed the death rates associated with intravenous challenge of these animals with specific antigen. rrSCF164 treatment induced the development of mast cells in Sl/Sld mice, and these mice exhibited tachycardia, but not death, after challenge with IgE and antigen. rrSCF164 treatment induced mast cell hyperplasia in +/+ mice, but the cardiopulmonary changes associated with passive anaphylaxis in these mice were virtually indistinguishable from those observed in control +/+ mice treated with vehicle instead of rrSCF164. Moreover, the highest dose of antigen challenge produced significantly fewer fatalities in rrSCF164-treated than in vehicle-treated +/+ mice (1/11 vs. 8/11, respectively, P < 0.01). Thus, in normal mice, chronic treatment with rrSCF164 induces mast cell hyperplasia but does not increase, and in certain respects diminishes, the severity of IgE-dependent anaphylactic reactions.
View details for Web of Science ID A1993MB16600009
View details for PubMedID 7691882
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MAST-CELLS CONTRIBUTE TO THE CHANGES IN HEART-RATE, BUT NOT HYPOTENSION OR DEATH, ASSOCIATED WITH ACTIVE ANAPHYLAXIS IN MICE
JOURNAL OF IMMUNOLOGY
1993; 151 (1): 367-376
Abstract
The mast cell is widely thought to contribute importantly to the cardiopulmonary changes associated with anaphylaxis, but much of the evidence for this is indirect. We, therefore, performed a detailed assessment of heart rate and pulmonary function during active anaphylaxis in genetically mast cell-deficient W/Wv or S1/S1d mice, the congenic normal (+/+) mice, and W/Wv mice repaired of their mast cell deficiency by transplantation of bone marrow from the congenic +/+ mice (+/+ BM-->W/Wv mice). For all five groups of mice, Ag challenge resulted in the death of more than two-thirds of the sensitized animals, whereas none of the nonsensitized control mice died as a result of Ag infusion. Sensitized normal (WBB6F1(-)+/+ or WCB6F1(-)+/+) mice and +/+BM-->W/Wv mice developed increases in heart rate that were significantly greater than those of nonsensitized +/+ mice or those of sensitized mast cell-deficient mice, indicating that mast cells contribute to the tachycardia observed in this form of active anaphylaxis. By contrast, even though some of the pulmonary changes associated with active anaphylaxis were more severe in +/+ than in mast cell-deficient mice, it was not clear to what extent this difference was mast cell dependent. W/Wv mice undergoing active anaphylaxis developed decreases in systemic arterial blood pressure that occurred more rapidly and were more severe than those observed in the congenic +/+ mice, indicating that the hypotension associated with this model of anaphylaxis also can occur by mast cell-independent mechanisms. We conclude that in this model of anaphylaxis mast cells: 1) are required for the development of the tachycardia response; 2) may contribute to, but are not essential for, production of decreases in lung function; and 3) are not necessary for the development of hypotension or death.
View details for Web of Science ID A1993LM57900038
View details for PubMedID 7686942
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SEQUENTIAL EXPRESSION OF TRANSFORMING GROWTH-FACTOR-ALPHA AND FACTOR-BETA(1) BY EOSINOPHILS DURING CUTANEOUS WOUND-HEALING IN THE HAMSTER
AMERICAN JOURNAL OF PATHOLOGY
1993; 143 (1): 130-142
View details for Web of Science ID A1993LM08500015
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HUMAN EOSINOPHILS CAN EXPRESS THE CYTOKINES TUMOR-NECROSIS-FACTOR-ALPHA AND MACROPHAGE INFLAMMATORY PROTEIN-1-ALPHA
JOURNAL OF CLINICAL INVESTIGATION
1993; 91 (6): 2673-2684
Abstract
By in situ hybridization, 44-100% of the blood eosinophils from five patients with hypereosinophilia and four normal subjects exhibited intense hybridization signals for TNF-alpha mRNA. TNF-alpha protein was detectable by immunohistochemistry in blood eosinophils of hypereosinophilic subjects, and purified blood eosinophils from three atopic donors exhibited cycloheximide-inhibitable spontaneous release of TNF-alpha in vitro. Many blood eosinophils (39-91%) from hypereosinophilic donors exhibited intense labeling for macrophage inflammatory protein-1 alpha (MIP-1 alpha) mRNA, whereas eosinophils of normal donors demonstrated only weak or undetectable hybridization signals for MIP-1 alpha mRNA. Most tissue eosinophils infiltrating nasal polyps were strongly positive for both TNF-alpha and MIP-1 alpha mRNA. By Northern blot analysis, highly enriched blood eosinophils from a patient with the idiopathic hypereosinophilic syndrome exhibited differential expression of TNF-alpha and MIP-1 alpha mRNA. These findings indicate that human eosinophils represent a potential source of TNF-alpha and MIP-1 alpha, that levels of expression of mRNA for both cytokines are high in the blood eosinophils of hypereosinophilic donors and in eosinophils infiltrating nasal polyps, that the eosinophils of normal subjects express higher levels of TNF-alpha than MIP-1 alpha mRNA, and that eosinophils purified from the blood of atopic donors can release TNF-alpha in vitro.
View details for Web of Science ID A1993LH12100043
View details for PubMedID 8514874
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DISTINCT PATTERNS OF EARLY RESPONSE GENE-EXPRESSION AND PROLIFERATION IN MOUSE MAST-CELLS STIMULATED BY STEM-CELL FACTOR, INTERLEUKIN-3, OR IGE AND ANTIGEN
EUROPEAN JOURNAL OF IMMUNOLOGY
1993; 23 (4): 867-872
Abstract
Stem cell factor (SCF) is encoded at the Sl locus of the mouse and is the ligand for the c-kit receptor. Recombinant rat SCF164 (rrSCF164) induces proliferation and promotes maturation of mouse mast cells in vitro and in vivo and can also induce c-kit receptor-dependent mouse mast cell degranulation. We now report that in both quiescent and non-quiescent mouse bone marrow-derived cultured mast cells (BMCMC) rrSCF164 induces increased mRNA levels for the "early response genes" c-fos, c-jun and junB but has only slight effects on the expression of junD. Recombinant mouse interleukin-3 (IL-3) also promotes proliferation of both quiescent and non-quiescent BMCMC. However, IL-3 induces increased expression of c-fos and junB only in quiescent BMCMC. Cross-linking of Fc epsilon receptor type I (Fc epsilon RI) on BMCMC by IgE and specific antigen induces a pattern of early gene expression very similar to that induced by rrSCF164. However, BMCMC stimulated through the Fc epsilon RI did not proliferate and, in comparison to control BMCMC, exhibited significantly decreased proliferation in response to rrSCF164 or IL-3. These results indicate that stimulation of BMCMC proliferation by IL-3 or rrSCF164 induces distinct patterns of early response gene expression and suggest that the proliferative effects of these growth factors may be mediated through distinct signal transduction pathways. Our data also point to previously unappreciated similarities between the effects of signaling through the c-kit receptor or the Fc epsilon RI on mast cell expression of fos and jun genes.
View details for Web of Science ID A1993KX06500014
View details for PubMedID 7681400
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CLONING AND FUNCTIONAL-ANALYSIS OF THE MOUSE C-KIT PROMOTER
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
1993; 191 (3): 893-901
Abstract
The c-kit protooncogene encodes a tyrosine kinase receptor expressed during ontogeny and adult life by several important and developmentally distinct cell lineages. Mice carrying germ line c-kit mutations exhibit deficiencies in most of these lineages, demonstrating that c-kit function is necessary for their normal development. To facilitate the identification of cis-acting elements which regulate tissue-specific c-kit expression, we cloned and characterized a mouse c-kit promoter which is functional in different cell types. A major c-kit transcription initiation site (TIS), located 58 bp upstream from the translation initiation codon, is utilized in mouse mast cells and in c-kit-positive cells in the mouse cerebellum. The effects of deletions in the 5' flanking region on reporter gene activity identify three short regulatory regions which function in both mouse and human c-kit positive cell lines. The nucleotide sequence of this region does not include CCAAT or TATA boxes but contains consensus binding sites for Sp1, Ap-2 and several short GA-rich elements which resemble binding sites for the ETS-domain proteins.
View details for Web of Science ID A1993KV40500019
View details for PubMedID 7682073
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MAST-CELL ACTIVATION ENHANCES AIRWAY RESPONSIVENESS TO METHACHOLINE IN THE MOUSE
JOURNAL OF CLINICAL INVESTIGATION
1993; 91 (3): 1176-1182
Abstract
Mast cell-deficient mutant mice and their normal littermates were used to determine whether activation of mast cells by anti-IgE enhances airway responsiveness to bronchoactive agonists in vivo. Pulmonary conductance was used as an index of airway response as the mice were challenged with increasing intravenous doses of methacholine (Mch) or 5-hydroxytryptamine (5-HT). Mast cell activation with anti-IgE enhanced pulmonary responsiveness to Mch in both types of normal mice (P < 0.0001 by analysis of variance) but not in either genotype of mast cell-deficient mouse. Additionally, anti-IgE pretreatment of genetically mast cell-deficient W/Wv mice whose mast cell deficiency had been repaired by infusion of freshly obtained bone marrow cells or bone marrow-derived cultured mast cells from congenic normal mice led to significant (P < 0.0001) enhancement of Mch responsiveness. 5-HT responsiveness was not significantly influenced by anti-IgE pretreatment in any of the mice studied. The data support the hypothesis that IgE-mediated activation of mast cells enhances pulmonary responsiveness to cholinergic stimulation.
View details for Web of Science ID A1993KR46100053
View details for PubMedID 8450046
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New concepts about the mast cell.
New England journal of medicine
1993; 328 (4): 257-265
View details for PubMedID 8418407
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REVERSIBLE EXPANSION OF PRIMATE MAST-CELL POPULATIONS INVIVO BY STEM-CELL FACTOR
JOURNAL OF CLINICAL INVESTIGATION
1993; 91 (1): 148-152
Abstract
Mast cell development in mice is critically regulated by stem cell factor (SCF), the term used here to designate a product of fibroblasts and other cell types that is a ligand for the tyrosine kinase receptor protein encoded by the proto-oncogene c-kit. However, the factors which regulate the size of mast cell populations in primates are poorly understood. Here we report that the subcutaneous administration of recombinant human SCF (rhSCF) to baboons (Papio cynocephalus) or cynomolgus monkeys (Macaca fascicularis) produced a striking expansion of mast cell populations in many anatomical sites, with numbers of mast cells in some organs of rhSCF-treated monkeys exceeding the corresponding values in control monkeys by more than 100-fold. Animals treated with rhSCF did not exhibit clinical evidence of mast cell activation, and discontinuation of treatment with rhSCF resulted in a rapid decline of mast cell numbers nearly to baseline levels. These findings are the first to demonstrate that a specific cytokine can regulate mast cell development in primates in vivo. They also provide the first evidence, in any mammalian species, to indicate that the cytokine-dependent expansion of tissue mast cell populations can be reversed when administration of the cytokine is discontinued.
View details for Web of Science ID A1993KK04200024
View details for PubMedID 7678600
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THE HUMAN RECOMBINANT C-KIT RECEPTOR LIGAND, RHSCF, INDUCES MEDIATOR RELEASE FROM HUMAN CUTANEOUS MAST-CELLS AND ENHANCES IGE-DEPENDENT MEDIATOR RELEASE FROM BOTH SKIN MAST-CELLS AND PERIPHERAL-BLOOD BASOPHILS
JOURNAL OF IMMUNOLOGY
1992; 149 (2): 599-608
Abstract
The gene product of the steel locus of the mouse represents a growth factor for murine mast cells and a ligand for the c-kit proto-oncogene receptor, a member of the tyrosine kinase receptor class of oncogenes (for review, see O. N. Witte. 1990. Cell 63:5). We have studied the effect of the human recombinant c-kit receptor ligand stem cell factor (rhSCF) on the release of inflammatory mediators from human skin mast cells and peripheral blood basophils and compared its activity to that of rhIL-3, rhSCF (1 ng/ml to 1 microgram/ml) activated the release of histamine and PGD2 from mast cells isolated from human skin. Analysis by digital video microscopy indicated that purified human skin mast cells (84 +/- 5% pure) responded to rhSCF (0.1 to 1 microgram/ml) challenge with a rapid, sustained rise in intracellular Ca2+ levels that was accompanied by secretion of histamine. A brief preincubation (10 min) of mast cells with rhSCF (0.1 pg/ml to 1 ng/ml) significantly enhanced (100 +/- 35%) the release of histamine induced by anti-IgE (3 micrograms/ml), but was much less effective on IgE-mediated release of PGD2. In contrast, a short term incubation with rhSCF did not potentiate the secretion of histamine activated by substance P (5 microM). A 24-h incubation of mast cells with rhSCF did not affect the release of mediators induced by anti-IgE (3 micrograms/ml), probably due to receptor desensitization, rhSCF (1 ng/ml to 3 micrograms/ml) neither caused release of histamine or leukotriene C4 (LTC4) release from leukocytes of 14 donors, nor induced a rise in intracellular Ca2+ levels in purified (greater than 70%) basophils. Brief preincubation (10 min) of leukocytes with rhSCF (1 ng/ml to 3 micrograms/ml) caused an enhancement (69 +/- 11%) of anti-IgE-induced release of histamine that was significant at concentrations as low as 3 ng/ml (p less than 0.05), whereas it appeared less effective in potentiating IgE-mediated LTC4 release. In contrast, a prolonged incubation (24 h) with rhSCF (0.1 pg/ml to 100 ng/ml) did not enhance the release of histamine or LTC4 induced by anti-IgE (0.1 microgram/ml), whereas rhIL-3 (3 ng/ml) significantly potentiated the release of both mediators.(ABSTRACT TRUNCATED AT 400 WORDS)
View details for Web of Science ID A1992JD12200033
View details for PubMedID 1378071
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THE RAT C-KIT LIGAND, STEM-CELL FACTOR, INDUCES C-KIT RECEPTOR-DEPENDENT MOUSE MAST-CELL ACTIVATION INVIVO - EVIDENCE THAT SIGNALING THROUGH THE C-KIT RECEPTOR CAN INDUCE EXPRESSION OF CELLULAR FUNCTION
JOURNAL OF EXPERIMENTAL MEDICINE
1992; 175 (1): 245-255
Abstract
Interactions between products of the mouse W locus, which encodes the c-kit tyrosine kinase receptor, and the Sl locus, which encodes a ligand for c-kit receptor, which we have designated stem cell factor (SCF), have a critical role in the development of mast cells. Mice homozygous for mutations at either locus exhibit several phenotypic abnormalities including a virtual absence of mast cells. Moreover, the c-kit ligand SCF can induce the proliferation and maturation of normal mast cells in vitro or in vivo, and also can result in repair of the mast cell deficiency of Sl/Sld mice in vivo. We now report that administration of SCF intradermally in vivo results in dermal mast cell activation and a mast cell-dependent acute inflammatory response. This effect is c-kit receptor dependent, in that it is not observed when SCF is administered to mice containing dermal mast cells expressing functionally inactive c-kit receptors, is observed with both glycosylated and nonglycosylated forms of SCF, and occurs at doses of SCF at least 10-fold lower on a molar basis than the minimally effective dose of the classical dermal mast cell-activating agent substance P. These findings represent the first demonstration in vivo that a c-kit ligand can result in the functional activation of any cellular lineage expressing the c-kit receptor, and suggest that interactions between the c-kit receptor and its ligand may influence mast cell biology through complex effects on proliferation, maturation, and function.
View details for Web of Science ID A1992GY43600030
View details for PubMedID 1370530
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EFFECT OF RECOMBINANT HUMAN C-KIT RECEPTOR LIGAND ON MEDIATOR RELEASE FROM HUMAN SKIN MAST-CELLS
19TH SYMP OF COLLEGIUM-INTERNATIONALE-ALLERGOLOGICUM : CHEMICAL MEDIATORS AND CELLULAR INTERACTIONS IN CLINICAL IMMUNOLOGY
KARGER. 1992: 323–25
View details for Web of Science ID A1992KL90000033
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REGULATION OF MAST-CELL PROLIFERATION, MATURATION AND FUNCTION BY STEM-CELL FACTOR, A LIGAND FOR THE C-KIT RECEPTOR
19TH SYMP OF COLLEGIUM-INTERNATIONALE-ALLERGOLOGICUM : CHEMICAL MEDIATORS AND CELLULAR INTERACTIONS IN CLINICAL IMMUNOLOGY
KARGER. 1992: 234–37
View details for Web of Science ID A1992KL90000014
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CYTOKINE PRODUCTION BY MAST-CELLS AND BASOPHILS
CURRENT OPINION IN IMMUNOLOGY
1991; 3 (6): 865-873
Abstract
Mast cells and/or basophils have been implicated in the expression of a wide variety of biological responses, including immediate hypersensitivity reactions, host responses to parasites and neoplasms, angiogenesis, tissue remodeling, and immunologically non-specific inflammatory and fibrotic conditions. Recent findings suggest that an important mechanism by which mast cells influence such biological responses is through the production of a broad panel of multifunctional cytokines. In contrast, the extent to which basophils can produce cytokines is uncertain.
View details for Web of Science ID A1991HB63700005
View details for PubMedID 1793528
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DIFFERENCES IN THE EXPRESSION OF THE CARDIOPULMONARY ALTERATIONS ASSOCIATED WITH ANTI-IMMUNOGLOBULIN-E-INDUCED OR ACTIVE ANAPHYLAXIS IN MAST-CELL DEFICIENT AND NORMAL MICE - MAST-CELLS ARE NOT REQUIRED FOR THE CARDIOPULMONARY CHANGES ASSOCIATED WITH CERTAIN FATAL ANAPHYLACTIC RESPONSES
JOURNAL OF CLINICAL INVESTIGATION
1991; 88 (2): 598-608
Abstract
We compared the changes in heart rate (HR), pulmonary dynamic compliance (Cdyn), and pulmonary conductance (GL) associated with three different models of anaphylaxis in genetically mast cell-deficient WBB6F1-W/Wv and congenic normal (+/+) mice. Intravenous infusion of a monoclonal rat anti-mouse IgE produced a marked tachycardia, diminutions in Cdyn and GL, and death in +/+ but not W/Wv mice, and +/+ mice sensitized to develop high circulating levels of IgE exhibited HR, Cdyn, and GL responses to rat anti-IgE challenge which were significantly less intense than those in nonimmunized +/+ mice. By contrast, virtually identical cardiopulmonary responses were observed in either +/+ or W/Wv mice challenged to elicit pure active anaphylactic responses or simultaneous active and anti-IgE-dependent anaphylaxis. These findings show that anaphylactic responses associated with significant tachycardia, reductions in Cdyn and GL, and death can occur in the virtual absence of tissue mast cells. This is true even though, in normal mice, such responses are associated with extensive degranulation of tissue mast cells. By contrast, certain models of anaphylaxis, such as that induced in nonsensitized mice by anti-mouse IgE, can not be elicited in the absence of mast cells.
View details for Web of Science ID A1991GA27600034
View details for PubMedID 1864969
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RELEASE OF BOTH PREFORMED AND NEWLY SYNTHESIZED TUMOR-NECROSIS-FACTOR-ALPHA (TNF-ALPHA)/CACHECTIN BY MOUSE MAST-CELLS STIMULATED VIA THE FC-EPSILON-RI - A MECHANISM FOR THE SUSTAINED ACTION OF MAST-CELL DERIVED TNF-ALPHA DURING IGE-DEPENDENT BIOLOGICAL RESPONSES
JOURNAL OF EXPERIMENTAL MEDICINE
1991; 174 (1): 103-107
Abstract
Mast cell-associated mediators are generally classified into two groups: the preformed mediators, which are stored in the cells' cytoplasmic granules and are released upon exocytosis, and the newly synthesized mediators, which are not stored but are produced and secreted only after appropriate stimulation of the cell. We now report that tumor necrosis factor alpha (TNF-alpha)/cachectin represents a new type of mast cell-associated mediator, in that IgE-dependent mast cell activation results in the rapid release of preformed stores of the cytokine followed by the synthesis and sustained release of large quantities of newly formed TNF-alpha. We also demonstrate that challenge with specific antigen induces higher levels of TNF-alpha mRNA at skin sites sensitized with IgE in normal mice or mast cell-reconstituted genetically mast cell-deficient WBB6F1-W/W1' mice than at identically treated sites in WBB6F1-W/W1' mice that are devoid of mast cells. These findings identify mast cells as a biologically significant source of TNF-alpha/cachectin during IgE-dependent responses and define a mechanism whereby stimulation of mast cells via the FC epsilon RI can account for both the rapid and sustained release of this cytokine.
View details for Web of Science ID A1991FU89700013
View details for PubMedID 1829107
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INDUCTION OF MAST-CELL PROLIFERATION, MATURATION, AND HEPARIN SYNTHESIS BY THE RAT C-KIT LIGAND, STEM-CELL FACTOR
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1991; 88 (14): 6382-6386
Abstract
We investigated the effects of a newly recognized multifunctional growth factor, the c-kit ligand stem cell factor (SCF), on mouse mast cell proliferation and phenotype. Recombinant rat SCF164 (rrSCF164) induced the development of large numbers of dermal mast cells in normal mice in vivo. Many of these mast cells had features of "connective tissue-type mast cells" (CTMC), in that they were reactive both with the heparin-binding fluorescent dye berberine sulfate and with safranin. In vitro, rrSCF164 induced the proliferation of cloned interleukin 3 (IL-3)-dependent mouse mast cells and primary populations of IL-3-dependent, bone marrow-derived cultured mast cells (BMCMC), which represent immature mast cells, and purified peritoneal mast cells, which represent a type of mature CTMC. BMCMC maintained in rrSCF164 not only proliferated but also matured. Prior to exposure to rrSCF164, the BMCMC were alcian blue positive, safranin negative, and berberine sulfate negative; had a histamine content of 0.08 +/- 0.02 pg per cell; and incorporated [35S]sulfate into chondroitin sulfates. After 4 wk in rrSCF164, the BMCMC were predominantly safranin positive and berberine sulfate positive, had a histamine content of 2.23 +/- 0.39 pg per cell, and synthesized 35S-labeled proteoglycans that included substantial amounts (41-70%) of [35S]heparin. These findings identify SCF as a single cytokine that can induce immature, IL-3-dependent mast cells to mature and to acquire multiple characteristics of CTMC. These findings also directly demonstrate that SCF can regulate the development of a cellular lineage expressing c-kit through effects on both proliferation and maturation.
View details for Web of Science ID A1991FW76100091
View details for PubMedID 1712491
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THE RAT C-KIT LIGAND, STEM-CELL FACTOR, INDUCES THE DEVELOPMENT OF CONNECTIVE-TISSUE TYPE AND MUCOSAL MAST-CELLS INVIVO - ANALYSIS BY ANATOMICAL DISTRIBUTION, HISTOCHEMISTRY, AND PROTEASE PHENOTYPE
JOURNAL OF EXPERIMENTAL MEDICINE
1991; 174 (1): 125-131
Abstract
Mast cell development is a complex process that results in the appearance of phenotypically distinct populations of mast cells in different anatomical sites. Mice homozygous for mutations at the W or S1 locus exhibit several phenotypic abnormalities, including a virtual absence of mast cells in all organs and tissues. Recent work indicates that W encodes the c-kit tyrosine kinase receptor, whereas S1 encodes a c-kit ligand that we have designated stem cell factor (SCF). Recombinant or purified natural forms of the c-kit ligand induce proliferation of certain mast cell populations in vitro, and injection of recombinant SCF permits mast cells to develop in mast cell-deficient WCB6F1-S1/S1d mice. However, the effects of SCF on mast cell proliferation, maturation, and phenotype in normal mice in vivo were not investigated. We now report that local administration of SCF in vivo promotes the development of connective tissue-type mast cells (CTMC) in the skin of mice and that systemic administration of SCF induces the development of both CTMC and mucosal mast cells (MMC) in rats. Rats treated with SCF also develop significantly increased tissue levels of specific rat mast cell proteases (RMCP) characteristic of either CTMC (RMCP I) or MMC (RMCP II). These findings demonstrate that SCF can induce the expansion of both CTMC and MMC populations in vivo and show that SCF can regulate at least one cellular lineage that expresses c-kit, the mast cell, through complex effects on proliferation and maturation.
View details for Web of Science ID A1991FU89700016
View details for PubMedID 1711559
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MOUSE SPLENIC AND BONE-MARROW CELL-POPULATIONS THAT EXPRESS HIGH-AFFINITY FC-EPSILON RECEPTORS AND PRODUCE INTERLEUKIN-4 ARE HIGHLY ENRICHED IN BASOPHILS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1991; 88 (7): 2835-2839
Abstract
Splenic and bone marrow cells from normal mice, and from mice that have been polyclonally activated by injection of anti-IgD antibody, contain cells that produce interleukin 4 (IL-4) in response to crosslinkage of Fc epsilon receptors (Fc epsilon R) or Fc gamma R or to ionomycin. Isolated Fc epsilon R+ cells have recently been shown to contain all of the IL-4-producing capacity of the nonlymphoid compartment of spleen and bone marrow. Here, purified Fc epsilon R+ cells are shown to be enriched in cells that contain histamine and express alcian blue-positive cytoplasmic granules. By electron microscopy, the vast majority of cytoplasmic granule-containing cells are basophils; they constitute approximately 25% and approximately 50%, respectively, of Fc epsilon R+ spleen and bone marrow cells from anti-IgD-injected mice. The Fc epsilon R- populations contain cells that form colonies typical of mast cells. The Fc epsilon R+ populations also contain cells that, upon culture with IL-3, form colonies of alcian blue-positive cells, but (in contrast to colonies derived from Fc epsilon R- populations) the colonies are small, and all the cells die within 2-3 weeks. The Fc epsilon R+ cells synthesize histamine during a 60-hr culture with IL-3, while the Fc epsilon R- cells do not. These results indicate that IL-4-producing Fc epsilon R+ cells are highly enriched in basophils.
View details for Web of Science ID A1991FE86400047
View details for PubMedID 1826367
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STEM-CELL FACTOR (SCF), A NOVEL HEMATOPOIETIC GROWTH-FACTOR AND LIGAND FOR C-KIT TYROSINE KINASE RECEPTOR, MAPS ON HUMAN-CHROMOSOME 12 BETWEEN 12Q14.3 AND 12QTER
SOMATIC CELL AND MOLECULAR GENETICS
1991; 17 (2): 207-214
Abstract
Recently a novel hematopoietic growth factor, stem cell factor (SCF), was cloned and demonstrated to be the ligand for the c-kit tyrosine kinase receptor. In the mouse, SCF is encoded by Sl (steel), a gene critical to the development of several distinct cell lineages during embryonic life and which has important effects on hematopoiesis in the adult animal. The Sl/SCF locus maps to the distal region of mouse chromosome 10, in the vicinity of genes that have been mapped to human chromosome 12. Here we report the use of somatic cell hybrid lines to localize SCF to the long arm of human chromosome 12, between 12q14.3 and 12qter. In addition to localizing the Sl homolog in man, these data provide further evidence for the conservation of synteny between the long arm of human chromosome 12 and the distal end of mouse chromosome 10.
View details for Web of Science ID A1991FD59400010
View details for PubMedID 1707188
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RECRUITMENT OF NEUTROPHILS DURING IGE-DEPENDENT CUTANEOUS LATE PHASE REACTIONS IN THE MOUSE IS MAST CELL-DEPENDENT - PARTIAL INHIBITION OF THE REACTION WITH ANTISERUM AGAINST TUMOR-NECROSIS-FACTOR-ALPHA
JOURNAL OF CLINICAL INVESTIGATION
1991; 87 (2): 446-453
Abstract
Much of the clinically important pathology associated with IgE-dependent disorders is thought to reflect the actions of the blood-borne leukocytes recruited during these responses. To evaluate the extent to which mast cells are responsible for the leukocyte infiltration associated with IgE-dependent cutaneous reactions, we attempted to elicit these responses in normal mice, genetically mast cell-deficient W/Wv mice, and in W/Wv mice selectively repaired of their mast cell deficiency by the intradermal injection of cultured mast cells derived from the congenic normal (+/+) mice. We found that the tissue swelling associated with IgE-dependent passive cutaneous anaphylaxis reactions developed rapidly and diminished markedly from 2 to 4 h after antigen challenge, but remained detectable for at least 24 h after elicitation of the responses. Infiltration of leukocytes (predominantly neutrophils) also occurred at these sites, but reached maximal levels 6-12 h after antigen challenge, persisted at high levels for 24 h, and largely waned by 48 h. Virtually all of the tissue swelling and leukocyte infiltration associated with IgE-dependent cutaneous reactions was mast cell dependent. Intradermal injection of 40 U of recombinant murine TNF-alpha (rmTNF-alpha) elicited neutrophil infiltration similar in magnitude and kinetics to that observed after IgE-dependent mast cell degranulation. A rabbit anti-rmTNF-alpha (R anti-rmTNF-alpha) antiserum, which was able to inhibit 84% of the neutrophil infiltration observed after i.d. injection of rmTNF-alpha, inhibited IgE-, and mast cell-dependent leukocyte infiltration by 47 +/- 7% in three separate experiments. These findings indicate that TNF-alpha contributes to mast cell-dependent recruitment of leukocytes during IgE-dependent cutaneous late phase reactions, but suggest that other mast cell-associated mediators probably also contribute to this response.
View details for Web of Science ID A1991EW29500010
View details for PubMedID 1991831
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ROLE OF MAST-CELLS IN ION-TRANSPORT ABNORMALITIES ASSOCIATED WITH INTESTINAL ANAPHYLAXIS - CORRECTION OF THE DIMINISHED SECRETORY RESPONSE IN GENETICALLY MAST CELL-DEFICIENT W/WV MICE BY BONE-MARROW TRANSPLANTATION
JOURNAL OF CLINICAL INVESTIGATION
1991; 87 (2): 687-693
Abstract
To investigate the role of mast cells in transport abnormalities during intestinal anaphylaxis, we examined responses to antigen in isolated intestinal preparations from ovalbumin-sensitized genetically mast cell-deficient WBB6F1-W/Wv (W/Wv) mice and congenic normal WBBGF1(-)+/+ (+/+) mice. Changes in ion transport (primarily secretion of chloride ions) were indicated by increases in short-circuit current (Isc). In tissues from +/+ mice, antigen caused increases in Isc which were significantly inhibited by antagonists to histamine (diphenhydramine) and serotonin (ketanserin), by a cyclooxygenase inhibitor (piroxicam) and by a neurotoxin (tetrodotoxin). In preparations from W/Wv mice, antigen-stimulated responses were approximately 30% of that in +/+ mice and were inhibited only by piroxicam. Responses to electrical transmural stimulation of nerves were approximately 50% in W/Wv versus +/+ mice, and were inhibited by antagonists of mast cell mediators in +/+ but not W/Wv mice. Reconstitution of mast cells in W/Wv mice by intravenous injection of +/+ bone marrow cells restored the normal responses to both antigen and nerve stimulation. Our results indicate that mast cell-dependent mechanisms are primarily responsible for the ion secretion associated with intestinal anaphylaxis, but that other cells are also involved. In addition, our data provide evidence for the functional importance of bidirectional communication between nerves and mast cells in the regulation of ion transport in the gastrointestinal tract.
View details for Web of Science ID A1991EW29500041
View details for PubMedID 1991852
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MAST-CELL NERVE ASSOCIATIONS IN THE RAT SMALL-INTESTINE - AN ELECTRON-MICROSCOPIC STUDY USING ACETYLCHOLINESTERASE ENZYME-HISTOCHEMISTRY
6TH INTERNATIONAL CONGRESS OF MUCOSAL IMMUNOLOGY
ELSEVIER SCIENCE PUBL B V. 1991: 455–456
View details for Web of Science ID A1991BU56R00111
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[I-125] FIBRIN DEPOSITION OCCURS AT BOTH EARLY AND LATE INTERVALS OF IGE-DEPENDENT OR CONTACT SENSITIVITY REACTIONS ELICITED IN MOUSE SKIN - MAST CELL-DEPENDENT AUGMENTATION OF FIBRIN DEPOSITION AT EARLY INTERVALS IN COMBINED IGE-DEPENDENT AND CONTACT SENSITIVITY REACTIONS
JOURNAL OF IMMUNOLOGY
1990; 145 (11): 3719-3727
Abstract
When elicited in the skin of mice, either IgE-dependent immediate hypersensitivity reactions or T cell-dependent contact sensitivity (CS) reactions result in local extravasation of [125I]fibrinogen and deposition of [125I]fibrin. However, these two types of reaction differ in kinetics and in requirement for IgE, mast cells, or T cells. In the present study, we investigated the kinetics and magnitude of [125I]fibrin deposition in combined IgE-dependent and CS reactions elicited simultaneously at the same site and compared the results with those obtained when the two reactions were elicited at separate sites. We found that [125I]fibrin deposition in pure IgE-dependent reactions was greater at 2 or 6 h after challenge than at 24 h, but that significant fibrin deposition persisted at those sites 24 h after challenge. In CS reactions, [125I]fibrin deposition was detected as early as 2 h after challenge, indicating that fibrin deposition accompanies the "early component" of CS detected by Van Loveren et al. with the use of measurements of tissue swelling. But much more [125I]fibrin deposition was present in CS reactions at 24 h than at 2 or 6 h after Ag challenge. When IgE-dependent and CS reactions were elicited at the same site, [125I]fibrin deposition at early intervals (2 to 6 h) after challenge was increased three- to 25-fold compared with that seen in isolated CS reactions, but at 24 h the results in the combined reactions were virtually identical to those in CS responses. Studies in genetically mast cell-deficient and congenic normal mice indicated that mast cells were required for expression of the IgE-dependent augmentation of [125I]fibrin deposition observed at early intervals in combined IgE-dependent and CS reactions, but not for the [125I]fibrin deposition associated with "pure" CS reactions. These findings indicate that the net effect of IgE-dependent mast cell activation on CS responses is to increase the fibrin deposition associated with these responses, but this effect is appreciated only at early intervals after elicitation of the reaction.
View details for Web of Science ID A1990EK39100026
View details for PubMedID 2246510
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MAST-CELLS AS A SOURCE OF MULTIFUNCTIONAL CYTOKINES
IMMUNOLOGY TODAY
1990; 11 (12): 458-464
Abstract
Mast cells have been implicated in the expression of a wide variety of biological responses, including immediate hypersensitivity reactions, host responses to parasites and neoplasms, immunologically non-specific inflammatory and fibrotic conditions, angiogenesis, and tissue remodeling and wound healing. However, the molecular basis for the action of the mast cell in many of these responses is obscure. In this review, John Gordon, Parris Burd and Stephen Galli suggest that the production of a broad panel of multifunctional cytokines may represent an important mechanism by which mast cells influence physiological, immunological and pathological processes.
View details for Web of Science ID A1990EN94000013
View details for PubMedID 2073318
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STEM-CELL FACTOR IS ENCODED AT THE SI-LOCUS OF THE MOUSE AND IS THE LIGAND FOR THE C-KIT TYROSINE KINASE RECEPTOR
CELL
1990; 63 (1): 213-224
View details for Web of Science ID A1990EB46100022
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HUMAN EOSINOPHILS EXPRESS TRANSFORMING GROWTH FACTOR-ALPHA
JOURNAL OF EXPERIMENTAL MEDICINE
1990; 172 (3): 673-681
Abstract
Transforming growth factor alpha (TGF-alpha) is a pleuripotential cytokine with diverse biological effects, including the ability to influence the proliferation of normal cells or neoplastic epithelial cells. Eosinophils are a subset of granulocytes that normally enter the peripheral tissues, particularly those beneath gastrointestinal, respiratory, and urogenital epithelium, where they reside in close proximity to the epithelial elements. In this study, we demonstrate that the great majority of eosinophils infiltrating the interstitial tissues adjacent to two colonic adenocarcinomas and two oral squamous cell carcinomas labeled specifically by in situ hybridization with a 35S-riboprobe for human TGF-alpha (hTGF-alpha). No other identifiable leukocytes in these lesions contained detectable hTGF-alpha mRNA. We also examined leukocytes purified from a patient with the idiopathic hypereosinophilic syndrome. 80% of these eosinophils, but none of the patient's neutrophils or mononuclear cells, were positive for hTGF-alpha mRNA by in situ hybridization, and 55% of these eosinophils were positive by immunohistochemistry with a monoclonal antibody directed against the COOH terminus of the mature hTGF-alpha peptide. Finally, the identification of the purified eosinophil-associated transcript as hTGF-alpha was confirmed by polymerase chain reaction product restriction enzyme analysis followed by Southern blot hybridization. In contrast to eosinophils from the patient with hypereosinophilic syndrome, the peripheral blood eosinophils from only two of seven normal donors had detectable TGF-alpha mRNA and none of these eosinophils contained immunohistochemically detectable TGF-alpha product. Taken together, these findings establish that human eosinophils can express TGF-alpha, but suggest that the expression of TGF-alpha by eosinophils may be under microenvironmental regulation. Demonstration of TGF-alpha production by tissue-infiltrating eosinophils and the eosinophils in the hypereosinophilic syndrome identifies a novel mechanism by which eosinophils might contribute to physiological, immunological, and pathological responses.
View details for Web of Science ID A1990DW49100001
View details for PubMedID 1696954
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MAST-CELLS AS A SOURCE OF BOTH PREFORMED AND IMMUNOLOGICALLY INDUCIBLE TNF-ALPHA CACHECTIN
NATURE
1990; 346 (6281): 274-276
Abstract
Tumour necrosis factor-alpha (TNF-alpha)/cachectin is a multifunctional cytokine that has effects in inflammation, sepsis, lipid and protein metabolism, haematopoiesis, angiogenesis and host resistance to parasites and malignancy. TNF-alpha was first described in activated macrophages, but certain mouse or rat mast cell populations (reviewed in refs 4,5) and some in vitro-derived human cells with cytochemical features of mast cells-basophils may also contain products similar to TNF-alpha. Here we present evidence that resident mouse peritoneal mast cells constitutively contain large amounts of TNF-alpha bioactivity, whereas cultured, immature mast cells vary in their TNF-alpha content. IgE-dependent activation of cultured or peritoneal mast cells induces extracellular release of TNF-alpha and augments levels of TNF-alpha messenger RNA and bioactivity. These findings identify mouse mast cells as an important source of both preformed and immunologically inducible TNF-alpha, and suggest that release of TNF-alpha by mast cells may contribute to host defence, the pathophysiology of allergic diseases and other processes dependent on TNF-alpha.
View details for Web of Science ID A1990DP45600067
View details for PubMedID 2374592
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ANATOMICAL VARIATION IN MAST-CELL NERVE ASSOCIATIONS IN THE RAT SMALL-INTESTINE, HEART, LUNG, AND SKIN - SIMILARITIES OF DISTANCES BETWEEN NEURAL PROCESSES AND MAST-CELLS, EOSINOPHILS, OR PLASMA-CELLS IN THE JEJUNAL LAMINA PROPRIA
LABORATORY INVESTIGATION
1990; 62 (5): 626-634
Abstract
Several studies have indicated that mast cells occur in close proximity to enteric nerves in the gastrointestinal tract of rats, man, and other mammalian species, and such intimate associations have been proposed as one of the anatomical bases of communication between the immune and the nervous systems. However, the specificity of anatomical associations between enteric nerves and mast cells, as opposed to other bone marrow-derived or lymphoid cells normally present in mucosal sites, is unclear. We used transmission electron microscopy to quantify the distances between mast cells and neural processes (nerve terminals or axons) in the small intestinal mucosa, right atrium, skin, and pulmonary parenchyma of normal rats, and in the small intestinal mucosa and lung parenchyma of rats that had undergone hyperplasia of the mast cell populations in these sites as a result of infection with the nematode Nippostrongylus brasiliensis. In the jejunal mucosa of normal rats, 8.0% of mast cells occurred within 100 nm of neural processes and an additional 11.0% between 101 and 500 nm of these structures; the corresponding figures for eosinophils were 3.3% (N.S. vs. mast cell value) and 23.3% (p less than 0.05 vs. mast cell value) and for plasma cells were 8.5% and 14.6% (N.S. vs. mast cell values). In the right atrium, 1.2% of mast cells occurred within 100 nm and an additional 13.4% within 101 and 500 nm of neural processes, whereas no mast cells were observed within 500 nm of neural processes in the pulmonary parenchyma or ear skin. Infection with N. brasiliensis increased by 61% the proportion of mast cells within 500 nm of neural processes in the jejunal mucosa and resulted in the appearance of mast cells in close association with these structures in the jejunal muscularis propria, but had no effect on the proportion of mast cells within 100 or 500 nm of neural processes in the pulmonary parenchyma. Acetylcholine esterase staining demonstrated dense networks of neural processes in the three sites where some mast cells were closely associated with these structures (jejunal mucosa and muscularis, right atrium) but not in the pulmonary parenchyma or ear skin. Taken together, our findings indicate that mast cells occur in close proximity to neural processes in sites where these structures are abundant, but that anatomical associations as close as those between mast cells and neural processes can also occur between such structures and other bone marrow-derived cells (eosinophils) or lymphoid cells (plasma cells) resident in the small intestinal mucosa.(ABSTRACT TRUNCATED AT 400 WORDS)
View details for Web of Science ID A1990DF15000012
View details for PubMedID 2342332
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PHORBOL 12-MYRISTATE 13-ACETATE INDUCED DEVELOPMENT OF FUNCTIONALLY ACTIVE MAST-CELLS IN W/WV BUT NOT SL/SLD GENETICALLY MAST CELL-DEFICIENT MICE
BLOOD
1990; 75 (8): 1637-1645
Abstract
The normal skin and other tissues of adult genetically mast cell-deficient WBB6F1-W/Wv or WCB6F1-Sl/Sld mice contain less than 1.0% the number of mast cells present in the corresponding tissues of the congenic normal (+/+) mice. We previously reported that mature dermal mast cells developed locally in the skin of W/Wv, but not Sl/Sld, mice at sites of chronic idiopathic dermatitis. We now report that the repeated application of phorbol 12-myristate 13-acetate (PMA) to the ear skin of either W/Wv or +/+ mice induces both dermatitis and a striking and dose-dependent increase in the number of dermal mast cells. The number of dermal mast cells at sites treated for 6 weeks with 5 micrograms PMA, three times per week, was 39 +/- 7/mm2 and 305 +/- 34/mm2 for W/Wv and +/+ mice, respectively; the corresponding values for vehicle-treated skin were 1.5 +/- 1.0/mm2 and 145 +/- 8/mm2, respectively. The PMA-induced dermal mast cells in W/Wv mice appeared mature by morphology, stained with the heparin-binding fluorescent dye, berberine sulfate, and were competent to express IgE-dependent passive cutaneous anaphylaxis responses. The development of mast cells was a local, not systemic, effect of PMA treatment. PMA treatment also induced dermatitis in both WCB6F1-Sl/Sld and +/+ mice, but was associated with increased numbers of dermal mast cells only in the WCB6F1(-)+/+ mice. PMA treatment had no detectable effect on the ability of bone marrow-derived cultured mast cells to survive in the skin of Sl/Sld mice. These findings establish a convenient model system for analyzing factors associated with the development of endogenous populations of mast cells in genetically mast cell-deficient W/Wv mice.
View details for Web of Science ID A1990CZ67500008
View details for PubMedID 2328315
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New insights into "the riddle of the mast cells": microenvironmental regulation of mast cell development and phenotypic heterogeneity.
Laboratory investigation; a journal of technical methods and pathology
1990; 62 (1): 5-33
View details for PubMedID 2404155
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GENERATION AND RECOGNITION OF VASOACTIVE-INTESTINAL-PEPTIDE BY CELLS OF THE IMMUNE-SYSTEM
CONF ON NEUROPEPTIDES AND IMMUNOPEPTIDES : MESSENGERS IN A NEUROIMMUNE AXIS
NEW YORK ACAD SCIENCES. 1990: 34–44
View details for Web of Science ID A1990BR83M00003
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SUBSTANCE-P-INDUCED AUGMENTATION OF CUTANEOUS VASCULAR-PERMEABILITY AND GRANULOCYTE INFILTRATION IN MICE IS MAST-CELL DEPENDENT
JOURNAL OF CLINICAL INVESTIGATION
1989; 84 (4): 1276-1286
Abstract
The undecapeptide substance P is thought to mediate both vasodilatation and augmented vascular permeability when released from sensory nerve endings in the skin. Substance P also induces mast cell degranulation in vitro or in vivo. However, the extent to which substance P-induced changes in vascular permeability are mast cell-dependent is unclear. We investigated this issue by injecting substance P and certain related peptides (substance P1-4, substance P4-11) into the skin of genetically mast cell-deficient WBB6F1-W/W or WCB6F1- SI/SId mice the congenic normal (+/+) mice, and W/W mice which had undergone selective local repair of their mast cell deficiency by intradermal injection of IL-3-dependent mast cells generated in vitro from the bone marrow cells of the congenic +/+ mice. Substance P induced significant augmentation of vascular permeability and significant cutaneous swelling when injected into normal mice at doses as low as 2 pmol i.d. Substance P also induced granulocyte infiltration, although the infiltrate were modest and were seen at doses of peptide from 5 to more than 20-fold higher than those required for induction of tissue swelling. The effects of substance P on tissue swelling, vascular permeability, and granulocyte infiltration were virtually entirely mast cell dependent. By contrast, substance P1-4 was inactive in our assays at 25 nmol/site, and substance P4-11 induced modest augmentation of vascular permeability, which was at least in part mast cell independent.
View details for Web of Science ID A1989AT80800031
View details for PubMedID 2477394
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INTERLEUKIN-3-DEPENDENT AND INTERLEUKIN-3-INDEPENDENT MAST-CELLS STIMULATED WITH IGE AND ANTIGEN EXPRESS MULTIPLE CYTOKINES
JOURNAL OF EXPERIMENTAL MEDICINE
1989; 170 (1): 245-257
Abstract
In response to IgE and specific multivalent antigen, mast cell lines (both growth factor-dependent and -independent) induce the transcription and/or secretion of a number of cytokines having a wide spectrum of activities. We have identified IL-1, IL-3, IL-5, IL-6, IFN-gamma, GM-CSF, JE, MIP1 alpha, MIP1 beta, and TCA3 RNA in at least two of four mast cell clones. The production of these products (except JE) is activation-associated and can be induced by IgE plus antigen. In selected instances cytokine expression can also be induced by activation with Con A or phorbol ester plus ionophore, albeit to levels less than those observed with IgE plus antigen. In addition, long-term mast cell clones and primary cultures of bone marrow-derived mast cells specifically release IL-1, IL-4, and/or IL-6 bioactivity after activation. These findings suggest that in addition to their inflammatory effector function mast cells may serve as a source of growth and regulatory factors. The relationship of mast cells to cells of the T lymphocyte lineage is discussed.
View details for Web of Science ID A1989AE68500018
View details for PubMedID 2473161
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ROLE OF MAST-CELLS IN ANAPHYLAXIS - EVIDENCE FOR THE IMPORTANCE OF MAST-CELLS IN THE CARDIOPULMONARY ALTERATIONS AND DEATH INDUCED BY ANTI-IGE IN MICE
JOURNAL OF CLINICAL INVESTIGATION
1989; 83 (4): 1375-1383
Abstract
We used genetically mast cell-deficient WBB6F1-W/Wv and WCB6F1-S1/S1d mice and the congenic normal (+/+) mice to investigate the effects of intravenous infusion of goat antimouse IgE on heart rate (HR), pulmonary dynamic compliance (Cdyn), pulmonary conductance (GL), and survival. In WBB6F1-+/+ and WCB6F1-+/+ mice, anti-IgE induced extensive degranulation of tracheobronchial mast cells, as well as significant elevation of HR, significant reductions in Cdyn and GL and, in some cases, death. In contrast, W/Wv and S1/S1d mice exhibited little or no pathophysiological responses and no mortality after challenge with anti-IgE. In W/Wv mice reconstituted with mast cells by intravenous administration of bone marrow cells derived from congenic +/+ mice (+/+ BM----W/Wv mice), anti-IgE induced extensive mast cell degranulation, as well as pathophysiological responses and mortality similar to those observed in WBB6F1-+/+ mice. These findings suggest a critical role for mast cells in the development of the cardiopulmonary changes and mortality associated with anti-IgE-induced anaphylaxis.
View details for Web of Science ID A1989T938800039
View details for PubMedID 2784802
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MAST-CELLS - IMMUNOLOGICALLY SPECIFIC EFFECTORS AND POTENTIAL SOURCES OF MULTIPLE CYTOKINES DURING IGE-DEPENDENT RESPONSES
SYMP ON IGE, MAST CELLS AND THE ALLERGIC RESPONSE
JOHN WILEY & SONS LTD. 1989: 53–73
View details for Web of Science ID A1989BP95D00004
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MAST-CELLS - IMMUNOLOGICALLY SPECIFIC EFFECTORS AND POTENTIAL SOURCES OF MULTIPLE CYTOKINES DURING IGE-DEPENDENT RESPONSES
CIBA FOUNDATION SYMPOSIA
1989; 147: 53-73
Abstract
Mast cells are critical effectors in many IgE-dependent responses, and the numbers and phenotype of certain mast cell populations can be influenced, through IL-3 and IL-4, by the same T cells that regulate IgE production. However, IgE can interact with cells other than mast cells, and different mast cell populations express significant variation in multiple important aspects of their phenotype, including mediator content and responses to cytokines and stimuli of activation. As a result it may be difficult to define the unique contributions of mast cells to IgE-dependent reactions. One approach for analysing the roles of various mast cell populations in individual biological responses is to attempt to elicit these reactions in mice in which the presence or absence of specific mast cell populations can be regulated experimentally. We have used genetically mast cell-deficient and mast cell-reconstituted mice to demonstrate that mast cells provide essential effector function in certain IgE-dependent responses involving the skin, stomach or lungs but are not necessary for the pulmonary alterations and death associated with active anaphylaxis. Similar approaches can be used to investigate the biological significance of the production, by mast cells stimulated with IgE and specific antigen, of cytokines similar or identical to IL-1, IL-3, IL-4, IL-5, IL-6, TNF-alpha/cachectin, IFN-gamma, GM-CSF, JE, MIP-1 alpha, MIP-1 beta and TCA3.
View details for Web of Science ID A1989CL39700004
View details for PubMedID 2515950
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MULTIPLE BIDIRECTIONAL ALTERATIONS OF PHENOTYPE AND CHANGES IN PROLIFERATIVE POTENTIAL DURING THE INVITRO AND INVIVO PASSAGE OF CLONAL MAST-CELL POPULATIONS DERIVED FROM MOUSE PERITONEAL MAST-CELLS
BLOOD
1988; 72 (3): 877-885
Abstract
Mouse peritoneal mast cells (PMC) express a connective tissue-type mast cell (CTMC) phenotype, including reactivity with the heparin-binding fluorescent dye berberine sulfate and incorporation of [35S] sulfate predominantly into heparin proteoglycans. When PMC purified to greater than 99% purity were cultured in methylcellulose with IL-3 and IL-4, approximately 25% of the PMC formed colonies, all of which contained both berberine sulfate-positive and berberine sulfate-negative mast cells. When these mast cells were transferred to suspension culture, they generated populations that were 100% berberine sulfate-negative, a characteristic similar to that of mucosal mast cells (MMC), and that synthesized predominantly chondroitin sulfate [35S] proteoglycans. When "MMC-like" cultured mast cells derived from WBB6F1-+/+ PMC were injected into the peritoneal cavities of mast cell-deficient WBB6F1-W/Wv mice, the adoptively transferred mast cell population became 100% berberine sulfate-positive. In methylcellulose culture, these "second generation PMC" formed clonal colonies containing both berberine sulfate-positive and berberine sulfate-negative cells, but exhibited significantly less proliferative ability than did normal +/+ PMC. Thus, clonal mast cell populations initially derived from single PMC exhibited multiple and bidirectional alterations between CTMC-like and MMC-like phenotypes. However, this process was associated with a progressive diminution of the mast cells' proliferative ability.
View details for Web of Science ID A1988Q102800007
View details for PubMedID 3416076
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PULMONARY RESPONSES TO BRONCHOCONSTRICTOR AGONISTS IN THE MOUSE
JOURNAL OF APPLIED PHYSIOLOGY
1988; 64 (6): 2318-2323
Abstract
Mice have been used in studies of the immunology or pathology of several different disorders affecting the lung. However, the value of the mouse for the analysis of pulmonary pathophysiology has been limited by the lack of methods for measuring lung function in the living animal. We report here the first method for measuring pulmonary conductance (GL) and compliance (Cdyn) in tracheostomized mechanically ventilated mice. We used this method to characterize the mouse's pulmonary responses to several putative bronchoconstrictor agonists. GL and Cdyn were decreased by intravenous infusions of methacholine, norepinephrine, or serotonin. Reproducible responses were not detected after infusions of histamine, prostaglandins D2 or F2 alpha, leukotrienes C4 or D4, substance P, or platelet-activating factor. The pattern of airway responsiveness to these agonists in the mouse is similar to that reported for the rat; in contrast to the rat, the mouse has many well-characterized strains or mutants with deficiencies of immunologic or inflammatory cells or mediators. As a result, this model offers unique advantages for identifying the roles of individual inflammatory cell types or mediators in pulmonary processes, including pulmonary anaphylaxis.
View details for Web of Science ID A1988N882300009
View details for PubMedID 2457008
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MAST CELL-DEPENDENT AMPLIFICATION OF AN IMMUNOLOGICALLY NONSPECIFIC INFLAMMATORY RESPONSE - MAST-CELLS ARE REQUIRED FOR THE FULL EXPRESSION OF CUTANEOUS ACUTE-INFLAMMATION INDUCED BY PHORBOL 12-MYRISTATE 13-ACETATE
JOURNAL OF IMMUNOLOGY
1988; 140 (7): 2356-2360
Abstract
Mast cells clearly are critical for the expression of some IgE-dependent responses, but their roles in other forms of inflammation are uncertain. We previously described a new model system for defining the unique contribution of mast cells to biologic responses in vivo, genetically mast cell-deficient WBB6F1-W/Wv mice that have undergone selective local repair of their mast cell deficiency by the injection of IL-3-dependent cultured mast cells derived from the congenic normal (WBB6F1-+/+) mice. Using this approach, we analyzed the contribution of mast cells to the acute inflammation induced by the epicutaneous application of PMA. Even though PMA can activate a wide variety of cell types that may contribute to acute inflammation, we found that mast cells were required for the full expression of the tissue swelling and leukocyte infiltration associated with the response to the agent in vivo. Thus, in WBB6F1-W/Wv mice selectively reconstituted with dermal mast cells by intradermal injection of cultured WBB6F1-+/+ mast cells into the left ear only, PMA induced approximately twice the tissue swelling and neutrophil infiltration in the mast cell-reconstituted left ears as in the contralateral control ears. This represents the first use of W/Wv mice locally reconstituted with mast cells to confirm the hypothesis that mast cells can represent an important amplification mechanism in acute inflammatory responses of nonimmunologic origin. It also defines a model system that may be generally useful for investigating mast cell-dependent and -independent aspects of acute inflammatory responses.
View details for Web of Science ID A1988M687900036
View details for PubMedID 3280681
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BASOPHIL INFLUX OCCURS AFTER NASAL ANTIGEN CHALLENGE - EFFECTS OF TOPICAL CORTICOSTEROID PRETREATMENT
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
1988; 81 (3): 570-574
View details for Web of Science ID A1988M618100014
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Basophil influx occurs after nasal antigen challenge: effects of topical corticosteroid pretreatment.
journal of allergy and clinical immunology
1988; 81 (3): 580-589
Abstract
Both the pattern of mediator release during the late-phase response (LPR) and the reduction of the LPR with corticosteroid pretreatment have suggested that basophils, not mast cells, represent the main source of histamine in the late response to nasal antigen challenge. We tested this hypothesis by examining alcian blue-stained cytospin slides of nasal washings obtained before and for 11 hours after nasal antigen challenge in 11 asymptomatic subjects with seasonal allergic rhinitis. In a double-blind manner, subjects received placebo or topical flunisolide (50 micrograms, each nostril, twice daily) for 1 week before antigen challenge. One month later, the challenge was repeated with the alternate pretreatment. On placebo-treatment days, a twelve-fold increase occurred in the number and a threefold increase in the percentage of alcian blue-stained positive cells in nasal washings in the LPR compared to baseline. At least 68% of these alcian blue-stained positive cells were basophils, as determined by light microscopic criteria. Alcian blue-stained cell influx correlated with increases in histamine levels in nasal washes (p less than 0.001). Topical steroid pretreatment blocked the influx of alcian blue-stained positive cells, as well as other inflammatory cells, including eosinophils, neutrophils, and mononuclear cells. Symptoms and mediator release were also blocked. These data demonstrate an influx of basophils and suggest that these cells are responsible for the histamine release observed in the LPR. Our findings indicate that pharmacologic control of basophil histamine release may represent a strategy for the treatment of a variety of chronic allergic diseases that are believed to resemble the LPR.
View details for PubMedID 2450113
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RAPID MICROWAVE FIXATION OF RAT MAST-CELLS .1. LOCALIZATION OF GRANULE CHYMASE WITH AN ULTRASTRUCTURAL POSTEMBEDDING IMMUNOGOLD TECHNIQUE
LABORATORY INVESTIGATION
1987; 57 (5): 592-599
Abstract
We defined the ultrastructural localization of chymase in rat peritoneal mast cells using standard aldehyde fixation and a newly described microwave fixation method (Login GR, Dvorak AM: Microwave energy fixation for electron microscopy. Am J Pathol 120: 230, 1985; Login GR, Stavinoha WB, Dvorak AM: Ultrafast microwave energy fixation for electron microscopy. J Histochem Cytochem 34:381, 1986) and postembedding immunogold labeling. Thin sections were exposed first to goat IgG anti-rat chymase and second to gold-conjugated rabbit Ig directed against goat IgG. By transmission electron microscopy, gold particles were localized to the matrix of cytoplasmic granules. Control sections treated with nonimmune sera did not exhibit labeling of mast cells. Thin sections treated simultaneously with purified rat mast cell chymase and anti-chymase antibody in competition studies, showed a marked reduction in granule staining. These findings demonstrate that a microwave fixation method can be used to rapidly fix cell suspensions for postembedding immunocytochemical studies.
View details for Web of Science ID A1987L178800014
View details for PubMedID 3479651
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I-125 FIBRIN DEPOSITION IN IGE-DEPENDENT IMMEDIATE HYPERSENSITIVITY REACTIONS IN MOUSE SKIN - DEMONSTRATION OF THE ROLE OF MAST-CELLS USING GENETICALLY MAST CELL-DEFICIENT MICE LOCALLY RECONSTITUTED WITH CULTURED MAST-CELLS
JOURNAL OF IMMUNOLOGY
1987; 139 (8): 2605-2614
Abstract
We investigated the clotting associated with IgE-dependent immediate hypersensitivity reactions in the mouse by injecting monoclonal mouse anti-dintrophenyl IgE antibodies i.d. and, the next day, administering 125I-guinea pig fibrinogen i.v. 10 to 30 min before i.v. antigen (2,4-dinitrophenylated human serum albumin) challenge. In normal mice, 2-hr passive cutaneous anaphylaxis (PCA) reactions were associated with substantial leakage of 125I-fibrinogen and deposition of 125I-fibrin. Thus, ears injected with IgE contained up to six times the total cpm of 125I and up to 30 times the cross-linked 125I-fibrin-associated cpm of 125I than did control ears. Several lines of evidence indicated that the 125I-fibrin deposition associated with the PCA reactions was dependent on the activity of mast cells: 1) Mast cell degranulation occurred at sites of PCA reactions. 2) Antigen-induced influx of 125I-fibrinogen and deposition of 125I-fibrin were virtually abolished by heating the IgE (56 degrees C, 1 hr) before i.d. injection. 3) Little or no IgE-dependent 125I-fibrinogen influx or 125I-fibrin deposition occurred in mast cell-deficient WBB6F1-W/Wv or WCB6F1-S1/S1d mice X 4) Adoptive transfer of cutaneous mast cell populations into WBB6F1-W/Wv mice (by each of three approaches: i.v. transplantation of normal bone marrow cells or local i.d. injection of cultured, growth factor-dependent mast cells 2 days or 9 to 10 wk before antigen challenge) conferred on the recipients the ability to express the 125I-fibrinogen influx and 125I-fibrin deposition associated with PCA reactions. These data demonstrate that 125I-fibrinogen influx and 125I-fibrin deposition occurs in association with PCA reactions in the mouse, and that the reaction is largely or entirely dependent on the function of cutaneous mast cells. The experiments also demonstrate the utility of a novel model system for the analysis of mast cell function in vivo: WBB6F1-W/Wv mice locally reconstituted with mast cells by the injection of mast cell populations generated in vitro.
View details for Web of Science ID A1987K320700016
View details for PubMedID 3655368
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STUDIES OF THE ROLE OF MAST-CELLS IN CONTACT SENSITIVITY RESPONSES - PASSIVE TRANSFER OF THE REACTION INTO MAST CELL-DEFICIENT MICE LOCALLY RECONSTITUTED WITH CULTURED MAST-CELLS - EFFECT OF RESERPINE ON TRANSFER OF THE REACTION WITH DNP-SPECIFIC CLONED T-CELLS
CELLULAR IMMUNOLOGY
1987; 109 (1): 39-52
Abstract
The role of mast cells in the elicitation of contact sensitivity (CS) responses was evaluated by transferring different aliquots of the same preparations of immune lymph node cells (I-LNC) into naive, genetically mast cell-deficient (WBB6F1-W/Wv or WCB6F1-S1/S1d) mice and the corresponding congenic normal (+/+) mice. We found that the 24-hr CS responses elicited in the recipient mast cell-deficient mice were statistically indistinguishable from those in the congenic +/+ mice according to four different criteria: micrometer measurements of ear swelling, ratios of the weight or [125I]iododeoxyuridine-labeled leukocyte infiltration-associated cpm in challenged and contralateral control ears, and amount of 125I-fibrin deposition. We also transferred I-LNC into WBB6F1-W/Wv mice which, 5 months earlier, had undergone local repair of their mast cell deficiency by the intradermal injection (into the left ear only) of growth factor-dependent cultured mast cells derived from congenic +/+ mice. When 24-hr CS responses were elicited in both ears of these mice, the reactions in the mast cell-reconstituted left ears were similar to those in the mast cell-deficient right ears. We also found that treatment of antigen-specific cloned T cells with reserpine in vitro markedly impaired their ability to transfer reactivity for CS, providing further evidence that reserpine can interfere with the expression of T-cell-mediated responses through effects independent of its action on mast cells.
View details for Web of Science ID A1987K369200004
View details for PubMedID 3498543
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ETHANOL-INDUCED ACUTE GASTRIC INJURY IN MAST CELL-DEFICIENT AND CONGENIC NORMAL MICE - EVIDENCE THAT MAST-CELLS CAN AUGMENT THE AREA OF DAMAGE
AMERICAN JOURNAL OF PATHOLOGY
1987; 128 (1): 131-140
Abstract
The authors used stereomicroscopy and planimetry to measure the area of glandular stomach mucosa acutely injured by oral ethanol in mast cell-deficient and congenic normal (+/+) mice, and examined the damaged areas in 1-mu sections. Ethanol caused degranulation and/or disruption of gastric mucosal mast cells, and, at certain concentrations of ethanol, mast cell-deficient WBB6F1-W/Wv or WCB6F1-Sl/Sld mice developed significantly less (43-90% less) acute gastric injury than either congenic +/+ mice or WBB6F1-W/Wv mice whose mast cells were restored by bone marrow transplantation from WBB6F1-+/+ mice. Nevertheless, ethanol produced detectable, and in some cases substantial, gastric injury even in the complete absence of mast cells. Thus, ethanol can produce some damage to the gastric mucosa independently of mast cells. But these data suggest that under certain circumstances mast cells can augment the area of acute gastric injury induced by ethanol.
View details for Web of Science ID A1987J061000015
View details for PubMedID 3605311
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CLONED ANOMALOUS KILLER-CELLS DERIVED FROM ALLOGENEIC MIXED LEUKOCYTE-CULTURE
CELLULAR IMMUNOLOGY
1987; 107 (1): 201-218
Abstract
In addition to allospecific cytotoxic lymphocytes, cytolytic effector cells capable of killing a broad range of targets are generated during mixed leukocyte culture (MLC). These cells, which have been previously called anomalous killer cells, are a distinct functional subset separate from natural killer cells or allospecific cytotoxic lymphocytes but display many characteristics of lymphokine-activated killers. In order to isolate anomalous killer cells for detailed analysis, we generated the cytolytic effectors from an allogeneic MLC using heat-inactivated stimulators. This treatment of the stimulator population abrogated the generation of classical allospecific cytotoxic lymphocytes but allowed the generation of anomalous killer cells which were subsequently cloned via limiting dilution. The clones derived by this method displayed the functional properties of anomalous killers seen in bulk MLCs. The clones demonstrated potent cytolytic activity against both NK-sensitive and NK-resistant tumor targets in vitro and also suppressed tumor growth in vivo. Ultrastructural studies revealed features similar to those of cloned antigen-specific cytolytic cells and clones with NK-like function. The cells expressed surface glycoproteins associated with both NK and T lymphocytes including Thy-1, Ly-2, T200, Qa-5, asialo GM1, and the antigens defined by the NK alloantisera NK-2.1 and NK-3.1. These cells may play an important role during early phases of the immune response, since cytolytic cells of broad specificity may protect the host until classical cytotoxic lymphocytes with restricted specificity are generated.
View details for Web of Science ID A1987H731500022
View details for PubMedID 2438052
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DEVELOPMENT OF LARGE NUMBERS OF MAST-CELLS AT SITES OF IDIOPATHIC CHRONIC DERMATITIS IN GENETICALLY MAST-CELL DEFICIENT WBB6F1-W/WV MICE
BLOOD
1987; 69 (6): 1661-1666
Abstract
The normal skin and other tissues of adult mast cell-deficient WBB6F1-W/Wv or WCB6F1-Sl/Sld mice contain less than 1.0% the number of mast cells present in the corresponding tissues of the congenic normal (+/+) mice. As a result, genetically mast cell-deficient WBB6F1-W/Wv or WCB6F1-Sl/Sld mice are widely used for studies of mast cell differentiation and function. We found that mast cells developed at sites of idiopathic chronic dermatitis in WBB6F1-W/Wv mice and that the number of mast cells present in the skin of WBB6F1-W/Wv mice was proportional to the severity of the dermatitis (in ear skin, there were 33 +/- 4 mast cells/mm2 of dermis at sites of severe dermatitis v 9 +/- 3 at sites of mild dermatitis, 0.8 +/- 0.3 in skin without dermatitis, and 100 +/- 7 in the normal skin of congenic WBB6F1-+/+ mice; in back skin, the corresponding values were 2.0 +/- 0.6, 1.1 +/- 0.9, 0.025 +/- 0.025, and 26.2 +/- 3.2). The development of mast cells was a local, not systemic, consequence of the dermatitis. Thus, WBB6F1-W/Wv mice with severe dermatitis lacked mast cells in skin not showing signs of dermatitis and also in the peritoneal cavity, stomach, cecum, and tongue. Idiopathic chronic dermatitis was not associated with the local development of mast cells in WCB6F1-Sl/Sld mice, a mutant whose mast cell deficiency is due to a mechanism distinct from that of WBB6F1-W/Wv mice. These findings may have implications for understanding the nature of the mast cell deficiency in WBB6F1-W/Wv and WCB6F1-Sl/Sld mice and for the use of these mutants to analyze mast cell differentiation and function.
View details for Web of Science ID A1987H623400018
View details for PubMedID 3580572
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NONSPECIFIC ESTERASE-ACTIVITY EXPRESSED IN WEIBEL-PALADE BODIES OF CLONED GUINEA-PIG AORTIC ENDOTHELIAL-CELLS
JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY
1987; 35 (5): 531-539
Abstract
We studied the localization of nonspecific esterase activities in cloned guinea pig aortic endothelial cells using ultrastructural cytochemistry. Weibel-Palade bodies (WPB), which are known to contain von Willebrand protein, were positive for esterase, defining a heretofore unrecognized activity of these organelles. Esterase activity was also found localized to the external surface of the plasma membrane, to cytoplasmic lipid bodies, and to the outer (cytoplasm-facing) surface of certain membrane-bound cytoplasmic vacuoles. Localization of esterase activity to these four discrete sites probably reflects the presence of a number of endothelial cell enzymes capable of hydrolyzing alpha-naphthyl acetate or butyrate. The physiological substrate and biological function of these enzyme activities are not presently understood.
View details for Web of Science ID A1987G874400002
View details for PubMedID 3559181
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GENETICALLY MAST-CELL-DEFICIENT W/WV AND SL/SLD MICE - THEIR VALUE FOR THE ANALYSIS OF THE ROLES OF MAST-CELLS IN BIOLOGIC RESPONSES INVIVO
AMERICAN JOURNAL OF PATHOLOGY
1987; 127 (1): 191-198
View details for Web of Science ID A1987G930000021
View details for PubMedID 3551622
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ULTRASTRUCTURAL CYTOCHEMICAL AND AUTORADIOGRAPHIC DEMONSTRATION OF NONSPECIFIC ESTERASE(S) IN GUINEA-PIG BASOPHILS
JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY
1987; 35 (3): 351-360
Abstract
We used ultrastructural autoradiographic and cytochemical methods to localize esterase activities in unstimulated guinea pig basophils and in basophils undergoing degranulation or recovery from degranulation. We used tritium-labeled diisopropylfluorophosphate (DFP) as a probe for serine enzymes and localized this probe by ultrastructural autoradiography to cytoplasmic granules of immature or mature unstimulated basophils, as well as to granules released by degranulating basophils. Ultrastructural cytochemistry using alpha naphthyl acetate (ANA) as substrate localized nonspecific esterase activity to extruded granules, either within the interiors of degranulation sacs or within granules completely separated from degranulating basophils. Extruded granules retained their esterase activity for as long as 24 hr after antigen-induced degranulation. The plasma membranes of unstimulated or degranulating basophils, as well as of basophils recovering from degranulation, displayed prominent cell surface ANA esterase ectoenzyme activity. Lipid bodies, organelles present in the cytoplasm of both control and recovering basophils, were also alpha naphthyl acetate esterase (ANAE)-positive. Thus, cytochemical and autoradiographic techniques localized esterase and/or [3H]-DFP-binding activities to cytoplasmic granules, lipid bodies, and cell surface of basophils, and these enzyme activities persisted during both degranulation and recovery from degranulation.
View details for Web of Science ID A1987G065000009
View details for PubMedID 3819377
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DEFECTIVE CYTOPLASMIC GRANULE FORMATION .1. ABNORMALITIES AFFECTING TISSUE MAST-CELLS AND PANCREATIC ACINAR-CELLS OF BEIGE MICE
LABORATORY INVESTIGATION
1987; 56 (3): 321-328
Abstract
Beige mice (C57BL/6-bgJ/bgJ) express the Chediak-Higashi syndrome, a genetically determined constellation of morphologic and functional abnormalities affecting cells that synthesize cytoplasmic granules; a similar disorder also occurs in humans and several other mammalian species. We used a computer-assisted morphometric approach to identify and quantitate the effect of the beige mutation on the structure of mast cell or pancreatic acinar cell cytoplasmic granules. Beige and control mouse mast cell or pancreatic acinar cell granules exhibited periodic, multimodal distributions of equivalent volumes in which the modes fell at volumes that were integral multiples of the volume of the "unit granule," whose volume (the "unit volume" or v1) was defined by the first mode in the granule equivalent volume distribution. But the modal frequency of the C57BL/6-bgJ/bgJ mast cell granule equivalent volume distribution fell at v1, a pattern consistent with a haphazard pattern of "unit granule" fusion, whereas the corresponding modal frequency for the control mast cell granules fell at v3, a pattern consistent with a "unit addition" model of granule fusion. In addition, the unit volume of beige mouse mast cell granules was 18 times that of control mouse mast cell granules. By contrast, the unit volume of beige mouse pancreatic acinar cell granules was only slightly (23%) greater than that of control cells. C57BL/6-bgJ/bgJ and control cells did not differ significantly in total cell or nuclear volume, or in the aggregate volume of their cytoplasmic granules. However, C57BL/6-bgJ/bgJ mast cells or pancreatic acinar cells contained significantly fewer granules than did their normal counterparts. These findings are consistent with the hypothesis that the beige mutation affects the formation of unit granules and also alters the pattern of aggregation and fusion of unit granules. The data also identify quantitative differences in the expression of the beige mutation in mast cells and pancreatic acinar cells.
View details for Web of Science ID A1987G541800011
View details for PubMedID 3821071
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PHENOTYPIC CHANGES OF BONE MARROW-DERIVED MAST-CELLS AFTER INTRAPERITONEAL TRANSFER INTO W/WV MICE THAT ARE GENETICALLY DEFICIENT IN MAST-CELLS
JOURNAL OF EXPERIMENTAL MEDICINE
1987; 165 (3): 615-627
Abstract
The ability of mouse IL-3-dependent, bone marrow culture-derived mast cells (BMMC) to generate serosal mast cells (SMC) in vivo after adoptive transfer to mast cell-deficient mice has been defined by chemical and immunochemical criteria. BMMC differentiated and grown from WBB6F1-+/+ mouse progenitor cells in medium containing PWM/splenocyte-conditioned medium synthesized a approximately 350,000 Mr protease-resistant proteoglycan bearing approximately 55,000 Mr glycosaminoglycans, as defined by gel filtration of each. Approximately 85% of the glycosaminoglycans bound to the cell-associated BMMC proteoglycans were chondroitin sulfates based upon their susceptibility to chondroitinase ABC digestion; HPLC of the chondroitinase ABC-generated unsaturated disaccharides revealed these glycosaminoglycans to be chondroitin sulfate E. As determined by heparinase and nitrous acid degradations, approximately 10% of the glycosaminoglycans bound to BMMC proteoglycans were heparin. In contrast, mast cells recovered from the peritoneal cavity of congenitally mast cell-deficient WBB6F1-W/Wv mice 15 wk after intraperitoneal injection of BMMC synthesized approximately 650,000 Mr protease-resistant proteoglycans that contained approximately 80% heparin glycosaminoglycans of approximately 105,000 Mr. Thus, after adoptive transfer, the SMC of the previously mast cell-deficient mice were like those recovered from the normal WBB6F1-+/+ mice that were shown to synthesize approximately 600,000 Mr proteoglycans that contained approximately 80% heparin glycosaminoglycans of approximately 115,000 Mr. As assessed by indirect immunofluorescence staining and flow cytometry using the B1.1 rat mAb (an antibody that recognizes an epitope located on the neutral glycosphingolipid globopentaosylceramide), approximately 5% of BMMC bound the antibody detectably, whereas approximately 72% of the SMC that were harvested from mast cell-deficient mice 15 wk after adoptive transfer of BMMC were B1.1-positive; approximately 82% of SMC from WBB6F1-+/+ mice bound the antibody. These biochemical and immunochemical data are consistent with the results of previous adoptive transfer studies that characterized mast cells primarily on the basis of morphologic and histochemical criteria. Thus, IL-3-dependent BMMC developed in vitro, cells that resemble mucosal mast cells, can give rise in vivo to SMC that express phenotypic characteristics of connective tissue mast cells.
View details for Web of Science ID A1987G292200003
View details for PubMedID 3102674
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ANTIGEN-INDUCED, IGE-MEDIATED DEGRANULATION OF CLONED IMMATURE MAST-CELLS DERIVED FROM NORMAL MICE
AMERICAN JOURNAL OF PATHOLOGY
1987; 126 (3): 535-545
Abstract
Cloned, immature mast cells derived from normal mice were passively sensitized with mouse monoclonal IgE antibodies with specificity for DNP, and then stimulated to degranulate with DNP35-HSA. Cells were fixed for transmission electron microscopy or recovered for quantitation of histamine release at various intervals up to 30 minutes after antigen challenge. The cloned mast cells rapidly extruded the contents of their immature granules (dense progranular material and membrane-bound vesicles) to the exterior via multiple openings in the plasma membrane. Degranulation was associated with striking activation of the cell surface, characterized initially by elongation of surface processes, as well as by close approximation of strands of rough endoplasmic reticulum to the cell surface and by the development of coated pits. At later times after stimulation, degranulated mast cells had released nearly all of their granules and exhibited angular surfaces lacking elongated processes. These findings demonstrate for the first time that cloned, immature mast cells, like their mature counterparts, can undergo classic morphologic release reactions involving exocytosis of granules.
View details for Web of Science ID A1987G520300016
View details for PubMedID 3826302
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ANALYSIS OF MAST-CELL FUNCTION IN BIOLOGICAL RESPONSES NOT INVOLVING IGE
INTERNATIONAL ARCHIVES OF ALLERGY AND APPLIED IMMUNOLOGY
1987; 82 (3-4): 269-271
Abstract
Mast cells are critical for the expression of certain IgE-mediated responses, but the precise contributions of mast cells to biological processes not involving IgE are obscure. We have employed genetically mast cell-deficient WBB6F1-W/Wv and WCB6F1-S1/S1d mice to investigate the roles of mast cells in several different biological responses. This work strongly suggests that mast cells are not required for the elicitation of contact sensitivity (CS) responses, suppressor T cell-dependent tolerance to CS, reserpine-induced inhibition of CS responses, or bleomycin-induced pulmonary fibrosis. By contrast, mast cells appear to contribute to the acute gastric injury induced by ethanol and the acute inflammation of the skin induced by croton oil.
View details for Web of Science ID A1987G942800009
View details for PubMedID 3570498
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BEIGE MOUSE MAST-CELLS GENERATED INVITRO - ULTRASTRUCTURAL ANALYSIS OF MATURATION INDUCED BY SODIUM-BUTYRATE AND OF IGE-MEDIATED, ANTIGEN-DEPENDENT DEGRANULATION
INTERNATIONAL ARCHIVES OF ALLERGY AND APPLIED IMMUNOLOGY
1987; 82 (3-4): 261-268
Abstract
We derived growth factor-dependent mast cell lines from C57BL/6-bgJ/bgJ ('beige') mouse bone marrow cells using techniques previously described for deriving mast cell lines from normal mice. According to examination by transmission electron microscopy, the cytoplasmic granules of cultured mast cells derived from beige mice were larger in size and fewer in number than those in cultured mast cells derived from normal C57BL/6 mice. Mast cells derived from beige mice underwent maturation when exposed to sodium butyrate, as judged by increased content of electron-dense material in the cytoplasmic granules. Cultured mast cells derived from beige mice also underwent IgE-mediated, antigen-dependent anaphylactic degranulation which was similar in its ultrastructural features to that described for cultured mast cells from normal mice. However, in mast cells not stimulated with IgE and antigen, fusion between individual cytoplasmic granules was observed more commonly in mast cells derived from beige mice than in normal mast cells. This might mean that these events are more common in C57BL/6-bgJ/bgJ mast cells, and/or that their resolution is slower and thus more easily captured by electron microscopy.
View details for Web of Science ID A1987G942800008
View details for PubMedID 3570497
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METHODS IN LABORATORY INVESTIGATION - INBRED GUINEA-PIG AORTIC ENDOTHELIAL-CELL CLONES - MODEL FOR STUDYING THE VASCULAR ENDOTHELIUM UNDER TOTALLY ISOLOGOUS CONDITIONS
LABORATORY INVESTIGATION
1986; 55 (6): 703-716
View details for Web of Science ID A1986F245300014
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I-125 FIBRIN DEPOSITION IN CONTACT SENSITIVITY REACTIONS IN THE MOUSE - SENSITIVITY OF THE ASSAY FOR QUANTITATING REACTIONS AFTER ACTIVE OR PASSIVE SENSITIZATION
JOURNAL OF IMMUNOLOGY
1986; 136 (6): 2018-2025
Abstract
We investigated the clotting associated with delayed hypersensitivity (DH) responses in the mouse by sensitizing the animals to the contactant oxazolone (Ox), and then administering 125I-guinea pig fibrinogen i.v. 10 to 30 min before antigen challenge 5 days later. Early (4 to 8 hr) contact sensitivity (CS) responses in immunized mice were barely detectable by three conventional measures of CS, but the total 125I-cpm in ears challenged with hapten was 3.6 to 4.5 X that in control ears challenged with vehicle alone; moreover, the amount of urea-insoluble cpm (cross-linked 125I-fibrin-associated cpm) in the reactions to Ox was 6.5-fold to 8.2-fold that present in the control reactions. In 24 hr reactions that were near peak intensity by measurements of ear swelling, ear weight ratios, and ratios of 125I-5-iodo-2-deoxyuridine-labeled leukocyte infiltration, the cpm in antigen-challenged ears exceeded that in control ears by 13-fold to 53-fold. In addition, antigen-challenged ears contained 27 to 300 X the urea-insoluble cpm present in control ears. 125I-Fibrin deposition was not a specific characteristic of CS reactions, because a small amount of urea-insoluble reactivity was also detected in some reactions to Ox in native mice. Nevertheless, the assay was exquisitely sensitive and readily detected quantitative differences between the immunologically specific and nonspecific reactions at very early intervals after challenge or with suboptimal doses of antigen. Furthermore, it was more sensitive than conventional tests of CS in detecting the reactions elicited in mice that had been passively sensitized to Ox by adoptive transfer of immune lymph node cells. Finally, we showed that the assay gave similar results when we tested CS reactions elicited in mast cell deficient WBB6F1-W/Wv and littermate normal (+/+) mice, demonstrating yet another similarity in the phenotype of DH reactions elicited in the presence or absence of mast cells.
View details for Web of Science ID A1986A391000014
View details for PubMedID 3485138
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HIGHER SUSCEPTIBILITY OF MAST-CELL-DEFICIENT W/WV MUTANT MICE TO BRAIN THROMBOEMBOLISM AND MORTALITY CAUSED BY INTRAVENOUS-INJECTION OF INDIA INK
AMERICAN JOURNAL OF PATHOLOGY
1986; 122 (3): 469-480
Abstract
(WB X C57BL/6)F1-W/WV mice possess a genetic defect in multipotential hematopoietic stem cells; the mice are anemic and lack mast cells. The authors injected diluted India ink intravenously into W/WV mice and congenic normal +/+ mice and searched for genetically determined differences in the development of complications of the injection. In both W/WV and +/+ mice, intravenous ink resulted in thrombocytopenia and markedly prolonged bleeding times, as well as prolonged partial thromboplastin and prothrombin times and reduced fibrinogen concentrations. These effects were similar in W/WV and +/+ mice, although the reduction in platelet counts was greater in W/WV mice. In addition, the mortality associated with ink injection was significantly higher in W/WV mice than in congenic +/+ mice. Most W/WV mice which died first exhibited paralysis, and examination under the dissection microscope revealed that ink injection resulted in significantly more cerebral thromboemboli in W/WV mice than in +/+ controls. Bone marrow transplantation from +/+ mice corrected both the mast cell deficiency and the anemia of W/WV mice and protected the W/WV recipients from the adverse consequences of ink injection. By contrast, +/+ mice rendered as anemic as W/WV mice by breeding did not exhibit increased morbidity and mortality after ink injection. (WC X C57BL/6)F1-Sl/Sld mice, which are anemic and lack mast cells because of a genetic defect different from that of W/WV mice, also exhibited increased morbidity and mortality after intravenous ink. Finally, mixture of ink with commercial heparin prior to intravenous injection markedly reduced the incidence of cerebral thromboembolism and death in W/WV mice. Taken together, these findings suggest that the increased morbidity and mortality exhibited by W/WV and Sl/Sld mice that received injected ink might be related to their mast cell deficiency rather than to their anemia. But measurement of the histamine content of the blood and various tissues of WBB6F1-+/+ mice injected with ink, and examination of their tissues in 1-mu sections, indicated that intravenous ink did not cause substantial mast cell degranulation. As a result, the possibility that mast cells protect +/+ mice from the adverse effects of intravenous ink by a mechanism other than degranulation and release of heparin, or that the differences in the response of W/WV or Sl/Sld mice and their +/+ littermates are due to defects other than their lack of mast cells, cannot be excluded.
View details for Web of Science ID A1986A494500010
View details for PubMedID 3513601
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CELLULAR AND VASCULAR MANIFESTATIONS OF CELL-MEDIATED-IMMUNITY
HUMAN PATHOLOGY
1986; 17 (2): 122-137
Abstract
The studies reviewed here emphasize both the complexity and the heterogeneity of cell-mediated immunity. In addition to the round cell infiltrate of the classic descriptions, cell-mediated immunity includes reactions that feature many types of inflammatory cells, that exert profound effects on the blood microvasculature, and that initiate extravascular clotting and, possibly, angiogenesis. The common denominator of all of these reactions is a subset or subsets of sensitized T lymphocytes that, on exposure to specific antigen, recruit and collaborate in other ways with one or more populations of circulating bone marrow-derived cells. Although the reactions generally resemble chronic inflammation by virtue of the lymphocytes and monocytes present, cell-mediated immunity may also take the guise of acute or subacute inflammation when neutrophils or eosinophils predominate and an entirely different morphologic pattern when basophils predominate, as in CBH. Tissue mast cells undergo changes (activation, proliferation) that are generally observed at later stages of delayed hypersensitivity, but no convincing evidence has been presented that these cells play an essential role in the elicitation of cell-mediated immunity. The concept that an essential prerequisite for the elicitation of delayed hypersensitivity is the mast cell-dependent generation of microvascular gaps, favoring inflammatory cell diapedesis, is clearly incorrect. First, lymphocytes fail to traverse certain of the vessels that exhibit such gaps (i.e., those of the SCV) in delayed hypersensitivity reactions in humans. Second, there is no diminution in the cellular infiltration associated with cell-mediated immunity reactions in mast cell-deficient mice. Cell-mediated immunity does not consist of an inflammatory cell infiltrate alone. The local microvasculature is rendered hyperpermeable to varying extents, with resulting extravasation of plasma proteins, including fibrinogen. The majority of extravasated fibrinogen is clotted to cross-linked fibrin, presumably as the result of the actions of procoagulants associated with fixed connective tissue cells and perhaps also because of the activity of infiltrating cells, such as monocytes/macrophages. Clotted fibrin forms a water-trapping gel, which accounts for the induration seen in many delayed hypersensitivity reactions. The microvasculature may also be affected in other ways. Endothelial cells may undergo hypertrophy and cell division or, alternatively, may exhibit profound and progressive injury.(ABSTRACT TRUNCATED AT 400 WORDS)
View details for Web of Science ID A1986A096400006
View details for PubMedID 3949336
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VESICULAR UPTAKE OF EOSINOPHIL PEROXIDASE BY GUINEA-PIG BASOPHILS AND BY CLONED MOUSE MAST-CELLS AND GRANULE-CONTAINING LYMPHOID-CELLS
AMERICAN JOURNAL OF PATHOLOGY
1985; 118 (3): 425-438
Abstract
Guinea pig basophils, cloned mouse mast cells, and cloned mouse granule-containing lymphoid cells were found to utilize a vesicular transport system to internalize eosinophil peroxidase (EPO) added in vitro. Kinetic analysis indicated that EPO internalization involved the binding of EPO to the plasma membrane, the formation of complex surface invaginations, and the movement of EPO-laden vesicles, tubules, and vacuoles toward the center of the cells. EPO became associated with multivesicular bodies in granule-containing lymphoid cells and mast cells, with immature granules in mast cells, and with mature granules in basophils. In other cells, the endogenous production of granule peroxidases (neutrophils and eosinophils) or the prior uptake of exogenous peroxidatic substances (some basophils) precluded cytochemical analysis of granules for EPO. Vesicular transport of EPO provides a possible explanation for the variable detection of peroxidase activity in mast cells or basophils. It also provides a mechanism for sequestration of this potentially toxic material or for its storage for possible future use.
View details for Web of Science ID A1985ADR5200010
View details for PubMedID 3976846
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CLONED MOUSE MAST-CELLS AND NORMAL MOUSE PERITONEAL MAST-CELLS - DETERMINATION OF SEROTONIN CONTENT AND ABILITY TO SYNTHESIZE SEROTONIN INVITRO
INTERNATIONAL ARCHIVES OF ALLERGY AND APPLIED IMMUNOLOGY
1985; 77 (1-2): 189-191
Abstract
We determined the serotonin (5-hydroxytryptamine, 5HT) content of growth factor dependent mouse mast cell lines or clones, and measured their ability to synthesize and store 3H-5HT from exogenous 5-hydroxy-[G-3H]-tryptophan (3H-5HTP) in vitro. Mast cells grown in vitro synthesized 3H-5HT from 3H-5HTP at rates equal to or greater than those of peritoneal mast cells freshly isolated from normal mice. Furthermore, under usual conditions of culture, mast cell lines or clones contained more 5HT than freshly isolated peritoneal mast cells.
View details for Web of Science ID A1985AJS2400038
View details for PubMedID 3874166
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REEVALUATION OF RESERPINE-INDUCED SUPPRESSION OF CONTACT SENSITIVITY - EVIDENCE THAT RESERPINE INTERFERES WITH LYMPHOCYTE-T FUNCTION INDEPENDENTLY OF AN EFFECT ON MAST-CELLS
JOURNAL OF EXPERIMENTAL MEDICINE
1985; 162 (6): 1935-1953
Abstract
It has been suggested that reserpine blocks expression of delayed hypersensitivity (DH) by depleting tissue mast cells of serotonin (5-HT), thereby preventing a T cell-dependent release of mast cell 5-HT necessary to localize and to amplify the DH response. However, reserpine blocks expression of DH in mast cell-deficient mice. We therefore decided to reevaluate the mechanism by which reserpine abrogates expression of cellular immunity, and investigated whether the drug might interfere with T cell activity in vitro or in vivo. At concentrations as low as 4 microM, reserpine profoundly suppressed baseline or antigen-augmented levels of [3H]thymidine incorporation by immune lymph node cells obtained from mice sensitized to the contactant oxazolone [I-LNC(Ox)]. This effect was observed both with I-LNC derived from normal mice and with I-LNC derived from congenitally mast cell-deficient W/Wv mice, cell preparations that lacked detectable mast cells, histamine, and 5-HT. Furthermore, treatment of I-LNC with reserpine (20 microM) for 1 h in vitro virtually abolished the ability of these cells to transfer CS to naive mice. This was not a cytolytic effect, as the viability of the I-LNC treated with reserpine was not affected, and washing of the reserpine-treated I-LNC before transfer fully restored their ability to orchestrate a CS response. The action of the drug was not mediated by an effect on mast cells, since the experiment could be performed using mast cell-deficient W/Wv mice as both donors and recipients of I-LNC. In addition, the effect was specific for the treated cells: mice that received reserpine-treated I-LNC(Ox) intravenously together with untreated I-LNC(DNFB) did not develop CS to Ox but responded normally to DNFB; and local intradermal injection of reserpine-treated I-LNC(Ox) which failed to transfer reactivity to Ox, did not interfere with the development of CS to DNFB at the same site. Finally, cotransfer experiments indicated that the effect of reserpine on the transfer of CS was not due to activation of suppressor cells. Our findings strongly suggest that whatever effects reserpine might have on immunologically nonspecific host cells, the drug's effects on sensitized T cells are sufficient to explain its ability to block cell-mediated immune responses in vivo.
View details for Web of Science ID A1985AWN6300015
View details for PubMedID 2933482
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SURFACE-MEMBRANE TRAFFIC IN GUINEA-PIG BASOPHILS EXPOSED TO CATIONIC FERRITIN
INTERNATIONAL ARCHIVES OF ALLERGY AND APPLIED IMMUNOLOGY
1985; 77 (1-2): 267-273
Abstract
Surface membrane traffic patterns can be influenced by a number of factors, including the functional state of the cell. We used transmission electron microscopy to investigate the fate of surface membrane in guinea pig basophils exposed to cationized ferritin (CF) in vitro. CF bound to the plasma membrane and was internalized on the membranes of vesicles and vacuoles, a process that was particularly prominent at the uropod of basophils exhibiting a polarized ('motile') configuration. The vesicles/vacuoles moved to the Golgi area, or, in the case of degranulating basophils, were observed in continuity with the degranulation sac, a structure formed largely by the fusion of individual cytoplasmic granule membranes. However, CF-positive vesicles were never observed to fuse directly with the membranes of intact cytoplasmic granules.
View details for Web of Science ID A1985AJS2400063
View details for PubMedID 4008083